Summary:
If user bind textureA and want to use it continuously, do not call glBindTexture(textureA) again.
But expect that textureA will be binding.
So EvasGL sould not change binded texture silently.
Restore texture to previous bound one after allocating new texture.
And when destroy texture, reset texture to 0 if it is current bound texture.
Test Plan: Tizen 3.0
Reviewers: wonsik, dkdk, cedric, jpeg
Reviewed By: jpeg
Differential Revision: https://phab.enlightenment.org/D4524
