Update wallet to 2.0.3

Diamond 2.0.3 new features

- Implement Fast Index. Provides very fast loading of the block chain from disk. (detail: no computation of block hashes is made. Possible to use the old behavior with full data verification by using -fastindex=0)

- Implement getnetworkhashps RPC (detail: presents the network hash rate outside of the getmininginfo RPC)

- Implement stakepower element in the getmininginfo RPC. (detail: provides programatic information for your total coin age)

- Implemented Qt wallet minting icon and mini-stats about minting in a tooltip. (detail: hover the mouse over the minting icon for the stats. Minting icons changes depending on whether the wallet is currently able to mint)

- Implement ‘unlock for minting only’. (detail: let’s you unlock the wallet, but it will still ask for a passphrase when sending coins. Very light protection from someone having access to your keyboard)

- Implement dnsseed nodes. (detail: will start functioning in few days)

- Implement coin control. (detail: let’s you chose which of your coin amounts are subject to send operations. Permits you select to which address the change should go, as well).

- Fix numerous Qt styling and compatibility issues. (detail: This task is not yet complete. More style fixes are under way)

- Fix numerous core hashing routines, text and general code cleanup.