Project implementation (WIP)

First implementation of the project notion + refactoring of voting
service.
Implementation of findProject

Implementation of the findProject method in the ProjectService class
Implementation of listProjects method in backend

Added the implementation for the listProjects method in the Project
Service
Project REST service implementation (test)

REST implementation of the Project service - needs IOC to make testing
possible.
Downgraded app engine version

Downgraded app engin version since the latest (1.8.3) requires maven
3.1.0 to build - will reconsider this decision later.
REST service for projects now available

Fixed configuration so the REST service for projects is now available.
Renaming vote service

Renamed VotingService to VoteRestService.