add a prototype for a missing SDL function
fix a freetype compile error when using this code to build a freetype library.
Remove some fake SDL functions: they don't fully satisfy the SDL interface so I'm including the SDL implementation directly.
I have some code that actually uses SDL_Delay: I'll make it a no-op myself
Kill a bunch of fixed-function GL stuff in lieu of regal
Relocate GL procs so that they can be implemented in C but the library version still be accessed through a function pointer, and always expose symbols through egl/glGetProcAddress even if GL emulation is disabled.

Conflicts:
	src/library_egl.js
	src/library_gl.js
	src/library_glut.js
	src/library_sdl.js
	src/modules.js
Revert "Relocate GL procs so that they can be implemented in C but the library version still be accessed through a function pointer, and always expose symbols through egl/glGetProcAddress even if GL emulation is disabled."

This reverts commit 4613ad96cd2c2b0f96737e87b1d0edb40ffabafd.
Revert "Kill a bunch of fixed-function GL stuff in lieu of regal"

This reverts commit ed7f796fcab2c723277c66c3a863cbc834fd1476.
Use #version 100 instead of #version 120 in shaders