Added missing transition_state decorator to reject_proposal

Ignore-this: 347c11c4981ac2364d363ed2a757ef0

darcs-hash:20100204161945-1e3d8-db85d94d294b1106be083396f9f5aa7d3d349499
Fixed _fail_proposal in case it is called from reject_proposal

Ignore-this: 43354c876086da46d4c6e4da53b28612

darcs-hash:20100204162005-1e3d8-a96e86649bae834709021ad145c3f18fef754f50