Quick update on softforks

[Tom Harding]

Bitcoin XT master branch and upcoming "F" release have support for the CSV soft fork and BIP9 (including the RPC interface).

The BIP109 (2MB) hard fork also continues to be signaled and supported.

P2Pool might need to be patched to set the 29th bit in the block version to signal 2MB support. This was necessary in the past.

Also of interest to miners that have customized CreateNewBlock -- XT has not adopted core's major rewrite of that function. That could be helpful in re-applying custom changes.