Filesystem root can be specified with sysname
Adds filesys cleanup to unit tests
Better cleanup in unit tests
Merge branch 'sysname_root' of git://github.com/lukecampbell/pyon into fs_sysname

Conflicts:
	extern/ion-definitions
	pyon/util/file_sys.py
Change default to /tmp/ion always
Bump ion-defs for fs config defaults
Merge pull request #371 from daf/fs_sysname

Change filesystem to use sysname prefix