Mir: Remove this experimental backend

As of the release of Mir 1.0, libmirclient has been deprecated[1] and
its developers recommend clients using it to switch to Wayland.  This
patch removes support for libmirclient and instruct users to use the
experimental Wayland backend instead.

[1] https://discourse.ubuntu.com/t/mir-news-28th-september-2018/8184

docs/Doxyfile.in

@@ -1573,7 +1573,6 @@ PREDEFINED             = GLFWAPI=                   \
                          GLFW_EXPOSE_NATIVE_WGL     \
                          GLFW_EXPOSE_NATIVE_X11     \
                          GLFW_EXPOSE_NATIVE_WAYLAND \
-                         GLFW_EXPOSE_NATIVE_MIR     \
                          GLFW_EXPOSE_NATIVE_GLX     \
                          GLFW_EXPOSE_NATIVE_COCOA   \
                          GLFW_EXPOSE_NATIVE_NSGL    \

docs/compat.dox

@@ -277,9 +277,4 @@ surfaces on Wayland.  If any of these extensions are not available, @ref
 glfwGetRequiredInstanceExtensions will return an empty list and window surface
 creation will fail.
 
-GLFW uses the `VK_KHR_surface` and `VK_KHR_mir_surface` extensions to create
-surfaces on Mir.  If any of these extensions are not available, @ref
-glfwGetRequiredInstanceExtensions will return an empty list and window surface
-creation will fail.
-
 */

docs/compile.dox

@@ -268,7 +268,6 @@ ramps and clipboard.  The options are:
  - @b _GLFW_WIN32 to use the Win32 API
  - @b _GLFW_X11 to use the X Window System
  - @b _GLFW_WAYLAND to use the Wayland API (experimental and incomplete)
- - @b _GLFW_MIR to use the Mir API (experimental and incomplete)
  - @b _GLFW_OSMESA to use the OSMesa API (headless and non-interactive)
 
 If you are building GLFW as a shared library / dynamic library / DLL then you

docs/news.dox

@@ -173,6 +173,14 @@ access functions @ref glfwGetX11SelectionString and @ref
 glfwSetX11SelectionString.
 
 
+@subsection news_33_mir_removal Experimental Mir support has been removed
+
+As per the release of Mir 1.0, the recommended API is now Wayland, the
+experimental Mir display server backend introduced in GLFW 3.1 has thus been
+removed.  To use the experimental Wayland backend, pass -DGLFW_USE_WAYLAND=ON
+to cmake where you previously passed the now-removed -DGLFW_USE_MIR=ON.
+
+
 @section news_32 Release notes for 3.2
 
 

docs/window.dox

@@ -337,7 +337,7 @@ constraint.  If no client API is requested, this hint is ignored.
 will fail.
 
 @par
-__Wayland, Mir:__ The EGL API _is_ the native context creation API, so this hint
+__Wayland:__ The EGL API _is_ the native context creation API, so this hint
 will have no effect.
 
 @par