They are now not exposed to the user at all, as their API will be
probably changed and reworked in the future to allow GLX/EGL-specific
extension to be used. Also this looks scary in the documentation.
We still want to target old Intel machines with OpenGL 2.1. Also moved
important information from constructor documentation to class
documentation. Who would look into constructor documentation for that?
Because with NaCl WindowContext doesn't make sense anymore, the classes
are now renamed:
* Contexts namespace -> Platform
* *WindowContext -> Application
Hopefully this is (one of) last crazy renaming runs.
Magnum.h now doesn't include anything except OpenGL headers, thus
changes in Math library don't trigger recompilation of everything, but
only of things really depending on it.
Math constants moved to separate file for similar reasons, de-inlined
some functions to remove the need for some #includes.