Specced and implemented DOA::SQL#update_statement with CPK support.
Specced and implemented DOA::SQL#update_statement with CPK support.

alloy/dm-core,ar-dm/ardm-core,tpitale/dm-core,tillsc/dm-core,joevandyk/dm-core,datamapper/dm-core,engineyard/dm-core,cardmagic/dm-core