fixed PYTHONPATH adding and exception handling in manage.py
A clearer example of savedevice.py made.

Methods in BNL\clientapi\idodspy\idodsclient.py
added:
- saveDevice
- retrieveDevice
- updateDevice

A clear example made in unitConversion\example\nsls2idods\savedevice.py,
how to save a device.
Merge branch 'master' of https://github.com/dejande/BNL
IDODS python client example bug repaired