Initial support for framed Thrift transports

See issue #6.

Add initial support for TFramedTransport in addition to
TBufferedTransport. This means HappyBase can connect to the different
Thrift server implementations in HBase 0.94.x. This is required for the
nonblocking, threadedselector, and hsha implementation. The threadpool
implementation requires TBufferedTransport.

This change is not exposed in the API yet.

happybase/api.py

@@ -12,7 +12,7 @@
 from struct import Struct
 
 from thrift.transport.TSocket import TSocket
-from thrift.transport.TTransport import TBufferedTransport
+from thrift.transport.TTransport import TBufferedTransport, TFramedTransport
 from thrift.protocol import TBinaryProtocol
 
 from .hbase import Hbase
@@ -93,7 +93,12 @@ def __init__(self, host=DEFAULT_HOST, port=DEFAULT_PORT, autoconnect=True,
         self.table_prefix = table_prefix
         self.table_prefix_separator = table_prefix_separator
 
-        self.transport = TBufferedTransport(TSocket(self.host, self.port))
+        socket = TSocket(self.host, self.port)
+        framed_transport = False  # TODO: make parameter, add docs
+        if framed_transport:
+            self.transport = TFramedTransport(socket)
+        else:
+            self.transport = TBufferedTransport(socket)
         protocol = TBinaryProtocol.TBinaryProtocolAccelerated(self.transport)
         self.client = Hbase.Client(protocol)
         if autoconnect: