Add support for use of directories instead of devices for OSD's
Ensure dev/patch exists before activating
Don't try to create osd-bootstrap key - it should always exist
Tweak handling for OSD startup
Fixups for osd bootstrap key handling
Tidy
Correct osd bootstrap key name
merging lp:~james-page/charms/precise/ceph-osd/dir-support as per https://code.launchpad.net/~james-page/charms/precise/ceph-osd/dir-support/+merge/182608