Fixed transaction listing to show correct ammounts for POS block rewards.
POS block rewards are shown as "interest" instead of "generate".
Modified the transaction list in the the QT interface to display
interest from Prof Of Stake blocks.  Also added "Stake Interest"
search option in the Transactions tab so people can see a list of
of their interest earned from their proof of stake stake blocks.

Note 1: You can now export all transactions to a CSV file and get a
total using Excel and the total will equal your wallet balance!
Note 2: No wallet rescan is required for this fix.
For RPC listaccounts, don't give "" account credit while staked coins
are not available due to being staked in an immature POS block.
Removed maturity check from CWalletTx::GetCredit and
CWalletTx::GetAvailableCredit (for consistency) and created new
function CWalletTx::IsMature() to be used on the outside when needed.
This change was needed to allow the QT client to list the correct
amount on an immature proof of stake transaction.

Also added immature stake coins to CWallet::GetImmatureBalance() so
the QT client will get a correct total.
Add immature stake interest to CWallet::GetNewMint

The RPC command getinfo shows newmint without including the
amount from an immature POS block. This change adds the
interest from new POS blocks to the newmint total.
Merge branch 'master' into fixTransList2
Changed description for POS transactions in QT transaction list.

Modified the description to show how many coins were input
in the "Source:" field, and how many coins were returned in
the "Credit:" field. This change is visible when you double
click on a POS transaction in the QT client.

Also uncapitalized "interest" for consistency with other
search tabs.
Removed unnecessary call to IsCoinStake().
Caught this boo-boo after using diff with white space ignore. Awesome!
Remove POS and POW transactions from Unconfirmed

POW and POS transactions should not be included
in the Unconfirmed total, since they have
another status called immature.
Merge pull request #24 from grokouser/fixTransList2

Fixed transaction lists in QT and RPC when POS blocks are generated by user.