[thrift] iolists and binaries in Erlang

[thrift] iolists and binaries in Erlang

Summary: three related changes:
 * for numeric types in tBinaryProtocol call effectful_write with binary(), not [char()]
 * tBinaryProtocol:writeString now takes either [char()], iolist(), or binary() ... now you can use any of the three where a Thrift string is required
 * tBufferedTransport now buffers by building an iolist() rather than Buffer++Data.  zomg.

Reviewed By: eletuchy

Test Plan: everything seems to work as usual, and binary() works as expected

Revert Plan: ok

git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@665447 13f79535-47bb-0310-9956-ffa450edef68