Add minting info icon and nicer unlock interface

Added minting GUI icon.
Replaced ugly unlock button with a nicer one.
Added menu items to lock/unlock wallet.
Added option to unlock for minting only.
Merge pull request #13 from keremhd/master

Remove misbehaving peer's reported block count from peer block counts wh...
Updated licence authors.

The previous commit adds code that came from blackcoin. Update COPYING
to include the same authors as blackcoin's licence.
Merge remote-tracking branch 'upstream/master'
Fix GUI lagging when client is syncing.
Merge pull request #14 from skwurp/master

Add minting info icon and nicer unlock interface
	modified:   src/checkpoints.cpp
	modified:   src/kernel.cpp
	modified:   src/version.h
	modified:   src/alert.cpp
Sort transactions by date instead of status.

List transactions by most recent date on the overview and transactions
pages. Sorting by status shows all the orphaned blocks first, which is
confusing.
Better fix for minting icon lagging the GUI.

Split updating user and network weights into a separate function. Update
them only every 30 seconds.
Fix proof-of-stake block signing.

Add back mistakenly removed SignBlock() in proof-of-stake section of
BitcoinMiner().
Merge pull request #15 from skwurp/pull-1

Critical: Fix proof-of-stake block signing.
Merge pull request #16 from skwurp/pull-2

Better fix for minting icon lagging the GUI.
Merge pull request #17 from skwurp/pull-3

Sort transactions by date instead of status.