Account: Implement Idendity trait (the PasswordInfo part)

This will enable Account to be used with securesocial.
oAuth{1,2}Info is still missing
UserStore: use JPA and Account for user storage

Replaces the Anorm based user storage.
UserStore: Fix deleteExpiredTokens (before vs. after)

We want to delete all tokens that have an expiration time that
is before now, i.e. small then now.
Merge pull request #29 from gicmo/user_db

Port UserStore to Account + JPA

Great: less ugly than expected :-)
Remove package test
Unit test stub for AbstractService
Test suite that runs all scalatest tests
Move test for serializer to respective util package

Add SerializerTest to TestAll
Test: create test assets
Model: avoid NullPointerException in compare()
Assets: fill database correctly
AbstractServiceTest: use assets in before and after
AbstractService: prepare for JPA use
Assets: small improvements

- createAbstract() method
- test data that covers more cases
AbstractService: implement methods and tests
Fix bugs that produced compile errors

- Fix removal of authors, affiliations and references on update and delete
- Add equals method to Model