Invalidate request cache after site updates.

Currently we're using a dodgy memory cache rather than Memcached or Redis.
We should probably change that, as I'm not certain this will invalidate correctly
with mod_tora, which I still don't entirely understand.
Merge branch 'master' of github.com:HaxeFoundation/haxe.org
tutorials -> articles
Merge branch 'master' of github.com:HaxeFoundation/haxe.org
Workarounds for faulty markdown generation
Get rid of the old proto/ directory
Use relative line height, apply to list items also
Merge branch 'master' of github.com:HaxeFoundation/haxe.org
Remove lib dependencies on client
Use explicit version numbers on all libraries

(Except markdown, still waiting for a release there)
Updated README, removed old install doc and admin file