[thrift] retool oop.erl, fix tBufferedTransportFactory.erl

[thrift] retool oop.erl, fix tBufferedTransportFactory.erl

Summary: oop.erl used to assume that an undef or function_clause meant a method wasn't defined, but sometimes a method does exist and an undef happens while it's executing.

Case in point, getTransport in tBufferedTransportFactory totally didn't work and instead of exiting, oop.erl fell back silently to tTransportFactory, so everywhere I thought I was talking to tBufferedTransport, I was talking directly to the tSocket.  borkborkbork.

Blame: all me baby

Reviewed By: eletuchy

Test Plan: channel server works

Revert Plan: ok

git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@665299 13f79535-47bb-0310-9956-ffa450edef68