creates prevent re-run

refactor to use chef commands
move ceph_bootstrap_osd_key to node['ceph']

we must wait for get osd-bootstrap keyring to finish

Last fixes
create /var/lib/ceph/mon/ceph-{hostname} directory if it doesn't exist.
remove ceph.mon.node attribute (more reflexion to this behaviour later)
fix typo for done file
service ceph-mon-all support restart and status
service must be restart immediately to launch ceph-mon

correct rebase
Don't use libraries for things that must be in attributes
Place service at the end of script to ensure that service is always enable and running after chef is execute
ceph support "status" command
remove useless require json in mon and add it in libraries
Manage starting mon with upstart
Use Mixlib::ShellOut instead of Chef::ShellOut