Fix for returned status code and .gitignore

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
Merge "Fix for returned status code and .gitignore"