Add GLFW source tree to src/external

We need the CMake stuff for wayland configuration.
Otherwise, we would have to replicate that ourselves.
This is the full 7ef34eb06de54dd9186d3d21a401b2ef819b59e7 tree except
for tests/ examples/ and docs/

src/external/glfw/CMake/modules/FindEpollShim.cmake

@@ -0,0 +1,17 @@
+# Find EpollShim
+# Once done, this will define
+#
+#   EPOLLSHIM_FOUND - System has EpollShim
+#   EPOLLSHIM_INCLUDE_DIRS - The EpollShim include directories
+#   EPOLLSHIM_LIBRARIES - The libraries needed to use EpollShim
+
+find_path(EPOLLSHIM_INCLUDE_DIRS NAMES sys/epoll.h sys/timerfd.h HINTS /usr/local/include/libepoll-shim)
+find_library(EPOLLSHIM_LIBRARIES NAMES epoll-shim libepoll-shim HINTS /usr/local/lib)
+
+if (EPOLLSHIM_INCLUDE_DIRS AND EPOLLSHIM_LIBRARIES)
+	set(EPOLLSHIM_FOUND TRUE)
+endif (EPOLLSHIM_INCLUDE_DIRS AND EPOLLSHIM_LIBRARIES)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(EPOLLSHIM DEFAULT_MSG EPOLLSHIM_LIBRARIES EPOLLSHIM_INCLUDE_DIRS)
+mark_as_advanced(EPOLLSHIM_INCLUDE_DIRS EPOLLSHIM_LIBRARIES)

src/external/glfw/CMake/modules/FindMir.cmake

@@ -0,0 +1,34 @@
+# FindMir
+# -------
+# Finds the Mir library
+#
+# This will will define the following variables::
+#
+# MIR_FOUND        - the system has Mir
+# MIR_INCLUDE_DIRS - the Mir include directory
+# MIR_LIBRARIES    - the Mir libraries
+# MIR_DEFINITIONS  - the Mir definitions
+
+
+find_package (PkgConfig)
+if(PKG_CONFIG_FOUND)
+  pkg_check_modules (PC_MIR mirclient>=0.26.2 QUIET)
+
+  find_path(MIR_INCLUDE_DIR NAMES mir_toolkit/mir_client_library.h
+                            PATHS ${PC_MIR_INCLUDE_DIRS})
+
+  find_library(MIR_LIBRARY NAMES mirclient
+                           PATHS ${PC_MIR_LIBRARIES} ${PC_MIR_LIBRARY_DIRS})
+
+  include (FindPackageHandleStandardArgs)
+  find_package_handle_standard_args (MIR
+                                     REQUIRED_VARS MIR_LIBRARY MIR_INCLUDE_DIR)
+
+  if (MIR_FOUND)
+    set(MIR_LIBRARIES ${MIR_LIBRARY})
+    set(MIR_INCLUDE_DIRS ${PC_MIR_INCLUDE_DIRS})
+    set(MIR_DEFINITIONS -DHAVE_MIR=1)
+  endif()
+
+  mark_as_advanced (MIR_LIBRARY MIR_INCLUDE_DIR)
+endif()

src/external/glfw/CMake/modules/FindOSMesa.cmake

@@ -0,0 +1,18 @@
+# Try to find OSMesa on a Unix system
+#
+# This will define:
+#
+#   OSMESA_LIBRARIES   - Link these to use OSMesa
+#   OSMESA_INCLUDE_DIR - Include directory for OSMesa
+#
+# Copyright (c) 2014 Brandon Schaefer <brandon.schaefer@canonical.com>
+
+if (NOT WIN32)
+
+  find_package (PkgConfig)
+  pkg_check_modules (PKG_OSMESA QUIET osmesa)
+
+  set (OSMESA_INCLUDE_DIR ${PKG_OSMESA_INCLUDE_DIRS})
+  set (OSMESA_LIBRARIES   ${PKG_OSMESA_LIBRARIES})
+
+endif ()

src/external/glfw/CMake/modules/FindVulkan.cmake

@@ -0,0 +1,46 @@
+# Find Vulkan
+#
+# VULKAN_INCLUDE_DIR
+# VULKAN_LIBRARY
+# VULKAN_FOUND
+
+if (WIN32)
+    find_path(VULKAN_INCLUDE_DIR NAMES vulkan/vulkan.h HINTS
+        "$ENV{VULKAN_SDK}/Include"
+        "$ENV{VK_SDK_PATH}/Include")
+    if (CMAKE_SIZEOF_VOID_P EQUAL 8)
+        find_library(VULKAN_LIBRARY NAMES vulkan-1 HINTS
+            "$ENV{VULKAN_SDK}/Lib"
+            "$ENV{VULKAN_SDK}/Bin"
+            "$ENV{VK_SDK_PATH}/Bin")
+        find_library(VULKAN_STATIC_LIBRARY NAMES vkstatic.1 HINTS
+            "$ENV{VULKAN_SDK}/Lib"
+            "$ENV{VULKAN_SDK}/Bin"
+            "$ENV{VK_SDK_PATH}/Bin")
+    else()
+        find_library(VULKAN_LIBRARY NAMES vulkan-1 HINTS
+            "$ENV{VULKAN_SDK}/Lib32"
+            "$ENV{VULKAN_SDK}/Bin32"
+            "$ENV{VK_SDK_PATH}/Bin32")
+        find_library(VULKAN_STATIC_LIBRARY NAMES vkstatic.1 HINTS
+            "$ENV{VULKAN_SDK}/Lib32"
+            "$ENV{VULKAN_SDK}/Bin32"
+            "$ENV{VK_SDK_PATH}/Bin32")
+    endif()
+elseif (APPLE)
+    find_library(VULKAN_LIBRARY vulkan.1 HINTS
+        "$ENV{VULKAN_SDK}/macOS/lib")
+    find_path(VULKAN_INCLUDE_DIR NAMES vulkan/vulkan.h HINTS
+        "$ENV{VULKAN_SDK}/macOS/include")
+else()
+    find_path(VULKAN_INCLUDE_DIR NAMES vulkan/vulkan.h HINTS
+        "$ENV{VULKAN_SDK}/include")
+    find_library(VULKAN_LIBRARY NAMES vulkan HINTS
+        "$ENV{VULKAN_SDK}/lib")
+endif()
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(Vulkan DEFAULT_MSG VULKAN_LIBRARY VULKAN_INCLUDE_DIR)
+
+mark_as_advanced(VULKAN_INCLUDE_DIR VULKAN_LIBRARY VULKAN_STATIC_LIBRARY)
+

src/external/glfw/CMake/modules/FindWaylandProtocols.cmake

@@ -0,0 +1,26 @@
+find_package(PkgConfig)
+
+pkg_check_modules(WaylandProtocols QUIET wayland-protocols>=${WaylandProtocols_FIND_VERSION})
+
+execute_process(COMMAND ${PKG_CONFIG_EXECUTABLE} --variable=pkgdatadir wayland-protocols
+                OUTPUT_VARIABLE WaylandProtocols_PKGDATADIR
+                RESULT_VARIABLE _pkgconfig_failed)
+if (_pkgconfig_failed)
+    message(FATAL_ERROR "Missing wayland-protocols pkgdatadir")
+endif()
+
+string(REGEX REPLACE "[\r\n]" "" WaylandProtocols_PKGDATADIR "${WaylandProtocols_PKGDATADIR}")
+
+find_package_handle_standard_args(WaylandProtocols
+    FOUND_VAR
+        WaylandProtocols_FOUND
+    REQUIRED_VARS
+        WaylandProtocols_PKGDATADIR
+    VERSION_VAR
+        WaylandProtocols_VERSION
+    HANDLE_COMPONENTS
+)
+
+set(WAYLAND_PROTOCOLS_FOUND ${WaylandProtocols_FOUND})
+set(WAYLAND_PROTOCOLS_PKGDATADIR ${WaylandProtocols_PKGDATADIR})
+set(WAYLAND_PROTOCOLS_VERSION ${WaylandProtocols_VERSION})

src/external/glfw/CMake/modules/FindXKBCommon.cmake

@@ -0,0 +1,34 @@
+# - Try to find XKBCommon
+# Once done, this will define
+#
+#   XKBCOMMON_FOUND - System has XKBCommon
+#   XKBCOMMON_INCLUDE_DIRS - The XKBCommon include directories
+#   XKBCOMMON_LIBRARIES - The libraries needed to use XKBCommon
+#   XKBCOMMON_DEFINITIONS - Compiler switches required for using XKBCommon
+
+find_package(PkgConfig)
+pkg_check_modules(PC_XKBCOMMON QUIET xkbcommon)
+set(XKBCOMMON_DEFINITIONS ${PC_XKBCOMMON_CFLAGS_OTHER})
+
+find_path(XKBCOMMON_INCLUDE_DIR
+    NAMES xkbcommon/xkbcommon.h
+    HINTS ${PC_XKBCOMMON_INCLUDE_DIR} ${PC_XKBCOMMON_INCLUDE_DIRS}
+)
+
+find_library(XKBCOMMON_LIBRARY
+    NAMES xkbcommon
+    HINTS ${PC_XKBCOMMON_LIBRARY} ${PC_XKBCOMMON_LIBRARY_DIRS}
+)
+
+set(XKBCOMMON_LIBRARIES ${XKBCOMMON_LIBRARY})
+set(XKBCOMMON_LIBRARY_DIRS ${XKBCOMMON_LIBRARY_DIRS})
+set(XKBCOMMON_INCLUDE_DIRS ${XKBCOMMON_INCLUDE_DIR})
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(XKBCommon DEFAULT_MSG
+    XKBCOMMON_LIBRARY
+    XKBCOMMON_INCLUDE_DIR
+)
+
+mark_as_advanced(XKBCOMMON_LIBRARY XKBCOMMON_INCLUDE_DIR)
+