[ANNOUNCE] Feature freeze tomorrow evening 9/18

[Owen O'Malley]

This is a reminder that we are branching Common, HDFS, and Map/Reduce  
tomorrow (9/18) at 4:45pm PDT. After the branch, only critical bug  
fixes can be put onto the branch without an explicit vote. The only  
current exception is the HDFS append work, which is expected to take a  
few more weeks.

-- Owen