Fixes #2519, clear error if using the default library path for EGL succeeds.
Fixes #2529, guard SDL_d3math.* with the proper defines
Updated iOS deployment target to iOS 5.1
Fixes #2512, handle configuration change messages sent by Wayland. Patch by Bryan Cain.
Include gl2platform.h in SDL_opengles2.h so we play nice with GLEW.

Based on feedback from Sven Bergström