Merge pull request #64 from bsmedberg/exp-branches

Use the new activeExperiment and activeExperimentBranch data
Add a utility for dealing with compressed files
Add the compressed test fixtures
Add a test for opening right away.
Add more tests
Add support for compressing too.
Update 'missing executable' to RuntimeError

If you're missing the 'xz' or 'lzma' binary, we now raise
RuntimeError instead of ValueError.
Add a helper to compress an existing raw file.

The 'compress_from' function lets you compress and optionally
remove an existing file.
Support multiple decompression types in job.py
Raise exception on unknown compression type.

Also cleanup comments and long lines.
Add a test for unknown compression type.
Use CompressedFile in process incoming.
Bug 986701: Script for cleaning FxOS 'ftu' pings.
Add MPL blurb
Support for source-bucket == dest-bucket
Add required __init__ files.
Don't try to remove nonexistent files.
Add a "min-date" parameter to skip old files.

We will use this to avoid reprocessing the entire history when
source-bucket and dest-bucket are the same.
Merge pull request #66 from mozilla/sanitize_fxos_bug986701

Sanitize FxOS pingIDs bug986701
Use with to ensure files are closed