Support registration of arbitrary NetworkParameters.
Add Block.removeTransaction()
Litecoin: Allow NetworkParameters to specify the block count for retarget.
Litecoin: Allow NetworkParameters to override the PoW function
Litecoin: Make bitcoin networkparameters constants protected
Litecoin: Make SeedPeers non-public (its Bitcoin-specific)
Litecoin: Make MAX_VALUE non-static.

This one isnt for merge, as it doesn't break bitcoinj directly and
is pretty trivially rebase-able.
Litecoin: LitecoinNetworkParameters
Litecoin: Add LitecoinWallet
Litecoin: Change PROTOCOL_VERSION.

Again, this is not a likely candidate for upstream inclusion, and
because the patch to upstream code is one line, maintaining this is
not an issue.
Litecoin: Add LitecoinPeerDBDiscovery that checks for NODE_BLOOM

This one is rather hacked too, but again should be rather easy to
maintain - just add the necessary functions that are now being
called and pass them through.