CSS forces tab background colour override which conflicts with other tab extensions PARTIAL FIX KNOWN

[stilez]

Code in win7.css and other skins overrides tabs backgrounds but kills other extensions trying to use tab colouring (ColourfulTabs, TabMixPlus etc)

See darrinhenein#13

I have written there, the code needed for the biggest fix, but other CSS probably needs removing as well.

I can't see a reason why a tab-bar positioning extension needs to do anything to manipulate tab background/opacity, other than honouring existing CSS. So the extension can be simplified further. Let other extensions (TMP etc) handle custom backgrounds, opactity etc. This extension shouldn't need to touch any of those, and if it's creating a new toolbar then copy the CSS from the existing bar instead of imposing new CSS?