Addede GitHub color scheme
Sorted options
Updated default colors and set many Python styles to inherited
Updated HTML and XML colors
Updated CSS, LESS and SASS colors
Updated Django and Mako templates colors
Updated Buildout, GQL, ReST and YAML colors
Updated JavaScript and CoffeeScript colors
Merge branch 'github-theme'
auto expressions spec: init duplication check
auto expressions spec: done duplication check
cache already checked plugins (IDEA-124828)