Set up the venv environment to let us use it for pre-release cross
testing to ensure we don't break consuming project unit tests.
Change-Id: If2bee203cb120b6c3b17a863fca2ece12651024f
For this purposes I added addiitional processing of original
exceptions at wsme/wsmeext/pecan.py. For exception's validation
special validator was added to wsme/wsmeext/utils.py. Also
functionality was reworked to be compatible with python3.3
Fixes bug#1214073
Change-Id: Ib1cd0b274bda11f62298848ebcd55b3f6641757c