cman: make ccsd startup optional and allow override of config loader
cman: make ccsd startup optional and allow override of config loader

implement support for CONFIG_LOADER envvar to select what config parsers
should cman use.

start ccsd only of we explicity select ccsconfig CONFIG_LOADER.

perform basic sanity check for other loaders into init script.

add some documentation on what loaders are available.

Signed-off-by: Fabio M. Di Nitto <510df3d038b805d3c95a0d349043a42f16d04605@redhat.com>

asp24/resource-agents,asp24/resource-agents,stevenraspudic/resource-agents,stevenraspudic/resource-agents,asp24/resource-agents,stevenraspudic/resource-agents