Monitor template

Hello,

I've made a couple of big mistakes on my previous PR:

- Monit does not load monitors on /etc/monit/monitrc.d;
- Ansible's with_fileglob only works for local files from where we're running the playbook.

This PR fixes the loading and unloading of monitors, saving a list of configured monitors on ansible facts, on /etc/ansible/facts.d/monit.fact.

Sorry for the mess and thank you.

PS: I've also added support 'host' checks and refactored the 'pidfile' variable into 'target', so that we can keep a single variable for all kinds of checks. I've also made 'rules' optional, so that we can have simple check on processes.