UP: Protected the docx import
add parallel-apply functionality using both threads and processes.  move the basic .to_vw method in streamers to use this method
flush stream in output worker
cleanup of to_vw
fixed to_vw in stream tests
a few more cleanups
remove threading reference in streamers
simplify the parallel apply function in the case when n_jobs = 1
UP: Protect the MySQLdb import.
Merge pull request #27 from columbia-applied-data-science/protected-import

UP: Protected the docx import
Merge pull request #29 from mdeland/stream_parallel

Parallel apply
Skip mysql tests if mysql not importable
Merge pull request #30 from ApproximateIdentity/protected-import

Protected import
Merge branch 'master' into file_io
Initial version of rosetta file format operations

This contains two functions. The first is textfiles_to_rosetta which can
create a 'rosetta file' (which is really just a sqlite3 database behind
the scences) from a folder containing text files. The second is
convert_rosetta_to_vw which converts a rosetta file to a format
compatible for vw.