Add a few changes (see description)

- Minimal Dark autocomplete menus background color is now dark
(http://imgur.com/xRYOIUI)
- Added "minimal_bold_tab_label": true/false setting (looks better on
windows)
- Better contrast (darker background) on selected buttons (in
find/replace menu). http://imgur.com/ZtN4UyF
- Removed side panel icons (introduced in sublime text 3) to keep
minimal look. Also default folder icons looked blurry.
Merge pull request #3 from rubenmv/master

Sure, thanks. Not sure about removing the icons though.