The commit also establishes a precedent of leaving off the `virtual`
keyword in overrides. Although not strictly necessary, I believe this is
good for readability because it makes it clear it is an override and not
a pure virtual function, and it helps keep line lengths shorter. We
should move towards eliminating the macro altogether, but the definition
has been left in with a note on deprecation so that in-progress work
will not suffer merge conflicts.
GLES drivers adapted, but only did make compile-tests.
git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/branches/ogl-es@6038 dfc29bdd-3216-0410-991c-e03cc46cb475
