Linguistic fix and reorganisation.
source readme: Document specific tested versions of dependencies instead of version ranges.

This doesn't necessarily mean that other versions of the dependencies won't work. However, it makes it clear what is guaranteed to work as expected and means that every changed dependency will always be noted.
This change was largely inspired by the recent problems with Python 2.7.4.
Merge branch 'release-2013.1' of git://git.nvaccess.org/nvda into release-2013.1jp
updated Japanese braille engine.