Upgrade httpclient to 4.1.2 (from 4.0.1)

httpclient 4.1.x contains a lot of goodies compared to the httpclient 4.0.x codeline, that thrift uses as of now.

Upgrading version of httpclient to 4.1.2 . (And explicitly specifying httpcore to be 4.1.3 , as well, the latter being an emergency fix).