Remove tox from requirements_dev to fix requirements_all
Monitoring API: fix the return codes

409 (conflict): the entry is not in the expected state
404: entry not found
Monitoring API: change the responses
Monitoring API: fix the doc
Monitoring API: tests for stats and status
Add requests in the dev's requirements
Cleaning some files
Handling plug in dropbox driver
setup.json using dropbox
Changing the chunk upload method
Fixing the upload on dropbox driver
Adding deletion on Dropbox driver
Adding tests
Add init file for the tests in dropbox
Fix the imports in the tests of dropbox
Start of a new approach.
New approach working base : get_chunk, upload_chunk.

- Fix the __init__

- Add a README and a manifest.json

- Add a script to retrieve an access token. Onitu now takes the
  access token key and secret as options to work.
Add the renewed version of change checking.

There still seems to be some issues with folders that don't exist yet
on Onitu side.

- README update
- manifest update
- PEP8 fix
Fix a typo in local storage test
Take the metadata 'path' name instead of filename in change polling thread.

The problem with the file name is that it's lowercased, and thus doesn't
represent the 'true' file name as Onitu stores it. Fortunately, the 'path'
metadata key contains the unchanged filename.

- Store the revision after each upload end. It permits to keep Onitu's
  revision up-to-date and to not trigger a change detection in the change
  polling thread.

- Add more comments

- Do the prefix handling stuff once and for all instead of once per loop
  turn in the check polling thread

- More error handling