Automate PO file updateing

make get-translations - gets translations from pootle.lm.org
make linguas - generates the LINGUAS file

The automation reduces errors in retreival as well as in building the
LINGUAS file.
Update translations before 2.5.1 final
Update copyrights to 2014
Add 2.5.1 release notes

Essentially a copy of 2.5.1-rc1
Improve requirements building

- Remove stray , from requirements
- At least use .whl files even if we don't parse the versions correctly
Update requirements

- Move to latest Translate Toolkit
- Refresh minimum and current at release requirements files.

Conflicts:

	requirements.txt