[R2.2 Release] create branch

[Liu, Ming (Ming)]

hi, all,

I found all important JIRA target for Apache Trafodion R2.2 release are in 
'complete' state. So I think it is a good time to create a branch for it to 
stabilize it.
Anyone still have something important for R2.2 release that we should wait for 
a while?

thanks,
Ming