Low: cluster: Use crm_node -l for node list

Don't use crmadmin since it is likely to be removed
in future versions of Pacemaker.
step agent skeleton
Low: corosync: corosync sub level
Low: main: More informative error on start failure
low: cluster: resolve hostnames before creating cluster
Low: cluster: split corosync functionality into own file
Dev: cibobjects: Remove dead code
Dev: scriptlets: Add scriptlets module
Low: crm_pssh: Limit scope of glob in pssh/get_output
WIP