Implemented themes

Added functionality to make it possible to change themes. Colors has
been moved from codeviewer.css to separate theme files.
Merge branch 'codeviewer-master' into codeviewer-feature-theme-#189
Fixed some conflicts. Some small fixes might have to be done

Conflicts:
	CodeViewer/basic.php
	CodeViewer/css/codeviewer.css
	CodeViewer/js/codeviewer.js
Merge branch 'codeviewer-feature-theme-#189' into codeviewer-master