[bliptv] Make sure video ID is a string
[googleplus] Fix upload_date detection
add capability to suppress expected warnings in tests
add tox configuration file for easy testing
[fixup] remove unnecessary commented function
Merge remote-tracking branch 'origin/tox'
Add basic --download-archive option

Often, users want to be able to download only videos they haven't seen before, despite the video files having been deleted or moved in the mean time.
When --download-archive FILE is given, the extractor and ID of every download is recorded in the specified file. If it is already present, the video in question is skipped.
Move try_rm to test helpers
Allow users to specify an age limit (fixes #1545)

With these changes, users can now restrict what videos are downloaded by the intented audience, by specifying their age with --age-limit YEARS .
Add rudimentary support in youtube, pornotube, and youporn.
[viddler] Add basic support (Fixes #1520)
release 2013.10.06
[generic] Clarify error messages
Call extracted property age_limit everywhere
Merge branch 'age_limit'
Remove superfluous parenthesis
Merge branch 'download-archive'

Conflicts:
	youtube_dl/YoutubeDL.py
	youtube_dl/__init__.py
[redtube] add age_limit
[vimeo] Recognize urls ending in a slash (fixes #1242)
Restore warning when user forgets to quote URL (#1396)
[jeuxvideo] Improve code quality (fixes #1567)