Branches for Sid

Author: Stuart Prescott
Revision Date: 2014-05-31 18:25:57 UTC

* Update packaging to reflect that newer versions of pyx support only
  python 3 and that they are separately packaged in the pyx3 source package.
* Update package descriptions to highlight that this is the python 2 version
  of pyx.
* Disable watch file since this package is tracking the obsolete branch.
* Add autopkgtest tests.
* Update standards version to 3.9.5 (no changes required).