extract CMAN code into a separate cookbook

CMAN code belongs in a separate cman cookbook, since it is not used by
all distros as part of the cluster stack.
README.md: improve formatting
fix recipe header
update more boilerplating
remove corosync.conf template from pacemaker cookbook

It's already in the corosync cookbook.
corosync.conf.erb: untabify indentation
add copyright header
parametrize some corosync cluster settings
update corosync.conf.erb header
corosync.conf.erb: move service section to top
corosync.conf.erb: align values
corosync.conf.erb: various tweaks
use consistent style when setting attributes