Add dependency name hints to CMake error messages

Fixes #1605.

(cherry picked from commit a43f545677)

CMakeLists.txt

@@ -71,7 +71,7 @@ if (MSVC)
         include(CheckIncludeFile)
         check_include_file(dinput.h DINPUT_H_FOUND)
         if (NOT DINPUT_H_FOUND)
-            message(FATAL_ERROR "DirectX 9 SDK not found")
+            message(FATAL_ERROR "DirectX 9 headers not found; install DirectX 9 SDK")
         endif()
         # Workaround for VS 2008 not shipping with stdint.h
         list(APPEND glfw_INCLUDE_DIRS "${GLFW_SOURCE_DIR}/deps/vs2008")
@@ -203,27 +203,27 @@ if (_GLFW_X11)
 
     # Check for XRandR (modern resolution switching and gamma control)
     if (NOT X11_Xrandr_INCLUDE_PATH)
-        message(FATAL_ERROR "The RandR headers were not found")
+        message(FATAL_ERROR "RandR headers not found; install libxrandr development package")
     endif()
 
     # Check for Xinerama (legacy multi-monitor support)
     if (NOT X11_Xinerama_INCLUDE_PATH)
-        message(FATAL_ERROR "The Xinerama headers were not found")
+        message(FATAL_ERROR "Xinerama headers not found; install libxinerama development package")
     endif()
 
     # Check for Xkb (X keyboard extension)
     if (NOT X11_Xkb_INCLUDE_PATH)
-        message(FATAL_ERROR "The X keyboard extension headers were not found")
+        message(FATAL_ERROR "XKB headers not found; install X11 development package")
     endif()
 
     # Check for Xcursor (cursor creation from RGBA images)
     if (NOT X11_Xcursor_INCLUDE_PATH)
-        message(FATAL_ERROR "The Xcursor headers were not found")
+        message(FATAL_ERROR "Xcursor headers not found; install libxcursor development package")
     endif()
 
     # Check for XInput (modern HID input)
     if (NOT X11_Xi_INCLUDE_PATH)
-        message(FATAL_ERROR "The XInput headers were not found")
+        message(FATAL_ERROR "XInput headers not found; install libxi development package")
     endif()
 
     list(APPEND glfw_INCLUDE_DIRS "${X11_Xrandr_INCLUDE_PATH}"

README.md

@@ -292,6 +292,7 @@ skills.
  - Alexandre Pretyman
  - Pablo Prietz
  - przemekmirek
+ - pthom
  - Guillaume Racicot
  - Philip Rideout
  - Eddie Ringle