Patch/fix sidebar template icons

1. Removes unnecessary highlighted sidebar image versions and make all other to use plain black (alpha only)
2. Removed unused icon source files (this are anyway accessible in Git history)
3. Uses `NSImageCell` for applying actual effect, which makes proper proper overlay effect depending on platform
4. Introduces pixel aligned PDF (scale independent icons) icons that preserve style of @afh previous commit, however give SVG source (instead Pixelmator which is proprietary), for details see cd94264
5. Uses SVG pixel aligned icons for history file icons, which makes them look sharp on all displays