GL_EXT_compiled_vertex_array
http://www.opengl.org/registry/specs/EXT/compiled_vertex_array.txt
	GL_ARRAY_ELEMENT_LOCK_FIRST_EXT 0x81A8
	GL_ARRAY_ELEMENT_LOCK_COUNT_EXT 0x81A9
	void glLockArraysEXT (GLint first, GLsizei count)
	void glUnlockArraysEXT (void)
