add support for perl plugins
use collectd::plugin resource and handle order and ensure parameters
add collectd-rrdtool package needed for RedHat
Merge pull request #167 from cfeskens/add-redhat-rrdtool-package

add collectd-rrdtool package needed for RedHat
correct minor lint style problems
Merge pull request #161 from ccin2p3/f/plugins-perl

add support for perl plugins
notify the collectd service when purging plugins

currently, if you have purge enabled and remove a plugin, the collectd service isn't notified. this should make it do that.
Merge pull request #169 from kitchen/patch-1

notify the collectd service when purging plugins