Fix GL_FFP_ONLY path to enable/disable vertex attribute arrays as a response to glEnable/DisableClientState instead of adjusting that during rendering.
Fix FFP GL emulation directives. The form !GL_FFP_ONLY is not supported, use GL_FFP_ONLY == 0 instead.
Fix GL emulation cleanup to properly update the state it changes.
Merge pull request #2031 from juj/fix_glemu_enabledisable

Fix glemu enabledisable