links for related generic objects implemented

Found your app useful but generic relations was missing.
Think it will be usefull for all and implemented it.

Cache used. Defauls:
getattr(settings, 'RELATIVES_CACHE_KEY', 'relatives_cache')
getattr(settings, 'RELATIVES_CACHE_TIME', int(60*60*24))

Also:
1. Template was updated and now it's more presentable.
2. Styles were moved to separate css file, placed as usually in 'static' dir.

Hope u like it :)
These should be in your [global `.gitignore`](https://help.github.com/articles/ignoring-files#create-a-global-gitignore) instead of in the `.gitignore` for every project you use.