Account:

* docu improved
* get_feed, get_blog, get_blog_entries added
* get_account_votes added
* fix timezone
Amount
* export to json and str fixed
Block
* change_block_number added
Blockchain
* get_estimated_block_num added
Comment
* dates and Amounts are now converted
* json_export adapted
* get_reblogged_by added
* delete_comment added
Storage
* 2 nodes removed from default
Utils
* timezone information added to formatTimeString
Unit tests
* more tests added for account, amount, comment, price and transaction