For windows compatibility

Alexandre Morignot authored Dec 05, 2014 and Romain Bignon committed Dec 13, 2014

The modules using this capability and galleroob have been corrected too

python modernize.py --no-six -f libmodernize.fixes.fix_print -w

With manual fixes as the import was put always on top.

refs #803

closes #1139

refs #806

This is recommended by Debian.
closes #618

There is now a "latest" collection (or "latest_nsfw").
The feature didn't look much used, since it didn't work on many
backends.
Using collections will make it easy to support other things
like most viewed, featured, etc.
As a bonus, I added tests for every backend with the feature.

Laurent Bachelier authored Mar 12, 2012 and Romain Bignon committed Mar 13, 2012

And fix some PEP8 style issues (mostly about spaces) while I was there.

refs #806

Use stderr and return codes >0 when it makes sense.
Loose return code conventions:
* 1 for generic errors
* 2 for user input errors
* 3 for remote errors (not found, etc.)
* 4 for not implemented