[RFC] vim-patch:7.4.318

Problem:    Check for whether a highlight group has settings ignores fg and bg color settings.
Solution:   Also check cterm and GUI color settings. (Christian Brabandt)

https://code.google.com/p/vim/source/detail?r=5c47dacf397c1c65d2dfc237b3ff395c66ec3d4d

The original patch included changes for the GUI feature. These are not included here.