further color changes

I changed the green/teal/orange slightly from the mock-ups, since they
were looking off on some monitors. Hopefully this is better. This also
has further color changes, mostly related to tree highlighting.
Merge remote-tracking branch 'origin/master' into color-refactor

Conflicts:
	styles/variables.less
	templates/workspace/sidebar/toc-branch.html
Merge pull request #62 from oerpub/color-refactor

further color changes