* implemented Domain model
* implemented creation of domains
* Proposal belongs to one Domain (not required at the moment)
(cherry-picked from 39f8672)
* user can add Proposal to Domain
* implemented UI navigation from Domains to Proposals and back to Domains
* user has 1 gold, 1 silver and 1 bronze vote across all domains and proposals
* NOTE: UI hasn't needs to be polished off
 *NOTE: all proposal data might become invalid (clean DB if features are not working properly)
(cherry-picked from 837b88e)
Merge remote-tracking branch 'origin/master'