added ftp.last.data timestamp to track last timestamp data was transferred in FTP syncer
don't override FTP last state, merge instead
actually, pretty much everywhere we shouldn't be overriding the state, just merging it
feature: Wukong 4.0.0

Squashed commit of the following:

commit b82bc418ab430ba4268ee2feca10b959a9f90a37
Author: Travis Dempsey <dempsey.travis@gmail.com>
Date:   Wed Mar 19 17:31:38 2014 -0500

    make all srp wu-versions line up

Change-Id: Id5e88c0a8325923e5572c9ff741a39bcebdefb0d