Clean up percona-server role

More whitespace stuff, use a hash loop for lineinfile, flip some logic
around to avoid red output, etc...
Clean up percona-arbiter

more logic fixes, task naming, white space
Merge pull request #583 from blueboxgroup/percona-cleanup

Clean up various percona roles.
libvirt: fix task name
allow for a prefix so we can specify ENV variables
use the prefix for os-api sensu checks
check_glance_store check
allow for 'disabled' checks
check-glance-store check instantiated - disabled for now
add check_glance_store.py to sensu sudoers
sensu_check supports env_vars
check_glance_store uses GLANCE_IMAGE_STORE env_var
enable check-glance-store sensu
rename check-glance-store.py
check-glance-store.py: pep8
sensu_check: fix set_arg_to_bool use before definition