Disable Wallet Mode for Litecoin

disablewallet=1 allows litecoind to operate with the BDB wallet disabled.  This is known to reduce the memory necessary to operate a relay-only node by between 40-200MB.  Pool servers and p2pool nodes can also operate with the disablewallet=1 by setting their payout address to an arbitrary address managed elsewhere.  This can enhance security of mining nodes.

* s/Wallet disabled.../Wallet disabled!/