Allow to theme UI components of the workbench

[be5invis]

Currently I cannot change the style of the editor "frame", for example, sidebar color, padding or font. This makes some themes (like Solarized) looks inconsistent with the editor UI.

[ZombieProtectionAgency]

For future reference Githubs issue tracker is not for support or feature suggestions. Feature suggestions already have a place over at vscodes uservoice and you can ask for help on StackOverflow with the [vscode] tag.

[chrisdias]

Sorry, there is not enough information here. What is the scenario, what is missing, etc.

[be5invis]

@chrisdias informations are added.

[chrisdias]

Ok, thanks, now i understand. @ZombieProtectionAgency its OK to submit feature requests here, we will eventually move from User Voice to here for those. Questions should be on Stack Overflow.

[ZombieProtectionAgency]

Thanks @chrisdias. Somebody else had let me know that too. I was trying to help direct people to the dedicated uservoice to help keep the git issue tracker from overflowing since it suddenly became open source with a pretty big following.

[be5invis]

So how about supporting a custom stylesheet in themes? Just like how Sublime Text did.

[bgashler1]

Related to #459

[bpasero]

#3112