made rhodecode work with celery 2.2, made some tasks optimizations(forget results)

added celeryconfig.py with just the definitions of hosts, it seams just this is needed to get celery working nice, all other config options are taken from .ini files. This is a temp workaround until i get the proper soltuion to this problem.

fixed Example celery config to ampq,
fixed session problems on models and celery,
implemented one base model as a parent for other

some fixups in cache, added fallback and cache invalidation when key not found in cached repos list,
added extra test, some other small fixes

refactoring for new vcs implementation
renamed all ._short and .raw_id into .short_id
updated dependency for vcs to 0.1.6

fixed lock decorator bug which didn't release the lock after func execution and rewrote the pidlock a little with Ask Solem suggestions!
added tredning languages stats

Removed config names from whoosh and celery,
celery is now configured based on the config name it's using
on celeryconfig. And whoosh uses it's own logger configured just for whoosh
Test creates a fresh whoosh index now, for more accurate checks
fixed tests for searching

Implemented password reset(forms/models/ tasks) and mailing tasks.
Added smtp mailer, configurations, cleaned user model