Bumped version numbers for 1.2.2 release build

Conflicts:
	bitcoin-qt.pro
	share/setup.nsi
Added minimum difficulty engine to ease transtition during block reward lowering.
Defined reduced rewards block to happen at block 60000
Reduced block rewards to start at reduced rewards block (at time of commit is after 4 halvings, will be 16 coins per block at current block number.)
Set minimum difficulty engine to activate for one block  alongside reduced rewards block to smooth transition to reduced rewards chain.
Fixed about banner to line up properly on about dialog