Refactoring of media/ hierarchy

To make things simpler, all external tools have been moved to media/external/.
Common CSS used by themes is now in media/css/.
fix css path in glyph.html
update: bootstrap 2.0.4 -> 2.3.2

also updates css imports, etc
fix: hack to avoid linebreak for css property visible-desktop

bug introduced in bootstrap 2.3 and fixed in 3.0, according to
https://github.com/twbs/bootstrap/issues/5407
top navigation bar: s/white/grey/ icons
left sidebar: add 'active' links

the name of the view is used to decide whether a link is active or not
Merge pull request #347 from matthieucan/refactor-media

Refactor media