Corrected the version number of PostgreSQL in the system documentation for mixing
Ported VcsEncryptedVoteRetainedMoreThanOnceIncidentUnitTest from 2011 to 2013
Refactoring: removed unused import from EncryptedVoteRetentionCounter
Ported VcsEncryptedVoteRetentionCounterUnitTest from 2011 to 2013, failing tests disabled
Ported NizkpCleansingUnitTest from 2011 to 2013