Missing explicit error message when assert

[bourmhe]

When doing an assert, please provide an explicit error message.

For this example, it will make the software stops without any explanation:
assert(glGetError() == GL_NO_ERROR);

It should be forbidden to have an assert without a clear error message to ease the debug. For this example, having the output of glGetError() https://www.khronos.org/registry/OpenGL-Refpages/es2.0/xhtml/glGetError.xml will really simplify the debug.