Merge pull request #1 from zaggino/master

Pull upstream.
Added new brackets ui variables.
Removed redundant CSS.
Fixed LESS errors.
Fixed dropdown menu styling and removed redundant CSS.
Partially styled dark diff styles.
Styled history viewer.
Settings styling.
Fixed toggle button styling.
Fixed caret color.
Put .btn.active styles in scope.
Tweaks.
Tweaks.
Better blue text for dark style and removed unused variables.
Merge pull request #688 from larz0/master

Brackets Git Dark UI