THRIFT-2767 hs: Transport.Empty is not externally available

Patch: Koen De Keyser

This Closes: #223
THRIFT-2722: js: Fix javascript service inheritance namespacing

Patch: Stig Bakken

This closes: #227
THRIFT-2757: py - Added integer limits checks in compact and JSON protocols

Client: Python
Patch: Bret Curtis

This closes: #234
THRIFT-2757: py - checkIntegerLimits optimized

Client: Python