Helvetica Neue / resized header for "tweets"
server side refactoring

- no manual sorting needed
- cronjob interval reduced to 10 min
- splitted one bigger db map into two simple maps
dont update the documents on every cron cycle. just insert new ones and forget about the old ones.
split helper methods to separate files
navigation added

- new logo typo
- navigation
- hide things under settings when logged out
- better form elements