update file.get() to use url-encoded uri 
Merge pull request #29 from UW-IBIC/master

Set file.get() to use a url-encoded URI
Merge pull request #28 from DavidJJ/master

Added ability to overwrite file using put.  updated some resource url's 
Update pyxnat/__init__.py

Updating version from 0.9.2.djj to 0.9.4 (9.3 was already in pypy?)