OpenGL Bindings (#16)

* Added opengl.c3l for opengl bindings

* Update README.md formatting

* Added bindings for all previous OpenGL versions (1.0 - 4.6)

* Added bindings for all previous OpenGL versions (1.0 - 4.6)

* Delete libraries/opengl.c3l/LICENSE

* Update README.md

libraries/opengl.c3l/README.md

@@ -0,0 +1,20 @@
+# OpenGL Bindings FAQ
+
+- OpenGL functions are renamed as follows: `glFunctionName` -> `gl::functionName`
+- Constant definitions keep the same name but are converted to C3 constants: `#define GL_FALSE 0` -> `const GL_FALSE = 0;`
+- Fixed length types are converted to the corresponding C3 types: `uint32_t` -> `int`
+- Variable length types are converted to the corresponding standard library compatibility types: `int` -> `CInt`
+- If a C typedef corresponds to a unique type that expects a subset of values it keeps the same name and gets converted to C3: `GLenum` -> `GLenum`
+- all `const char *` sequences are converted to `ZString`
+
+# Older OpenGL Versions
+
+- All older versions of OpenGL are supported.
+- By default the most recent version is used.
+- The specific version used can be set as follows:
+```C3
+module opengl;
+const GL_VERSION = 33;
+```
+- The `GL_VERSION` is just the desired opengl version without the decimal point (so version 1.0 becomes 10, and 4.5 becomes 45)
+- Once the version is set only the functions and definitions from that version can be used. The only exception is anything defined in opengl.c3i as global.