Example plugin to send out mails on error

Fix inventory API groups

This is useful mostly for playbooks that run unattended and for a limited set of systems. In case of provisioninging this plugin (together with a final mail action) helps to get notified when something went wrong, or when the installation finished successfully.

Unfortunately, there is no way to enable/disable a plugin from a playbook. So installing the plugin means all other use-cases (provisioning, troubleshooting, reporting or management) all send mails on failure. Something we may want to fix in the future...

Workaround for when HP iLO is in a state it won't accept requests

Add a yaml format inventory plugin.

Openstack rackspace update

Module network_facts to gather facts based on network information

Typo in example section for 'setup' module docs.

This fixes #1265.

This workaround is recommended from HP iLO's documentation, but may not be sufficient in all cases. Time will tell.

I also made a few cosmetic changes with no impact.

Sigh, another retypo

Fixes to documentation

Makes ports configurable for fireball.  Note port defaults really belong in the connection plugins, not runner, which can be refactored later.

Various small fixes to boolean usage and defaults

cron feature (w/o tests)

Keep the man3 directory. 'make docs' breaks without it.

Add this module's namespace to the 'module_' namespace.

Fix typo in service module docs

Add inventory variables for hosts not in the play to hostvars.

Look up only when requested and cache the result.

Much like we currently have *setup* register the variable `module_setup`, we would like other facts-modules register their own namespace. This means that:

 - *network_facts* registers `module_network`
 - *hpilo_facts* registers `module_hw`
 - *vsphere_facts* registers `module_hw`

In retrospect, it would have made more sense to have `setup` register `module_ansible` instead as the setup module uses the `ansible_` namesepace.

Having the `module_` namespace allows us to check whether a certain namespace has already been loaded so we can avoid running the facts module a second time using only_if.

```yaml
 - action: network_facts host=${ansible_hostname_short}
   only_if: is_unset('$module_network')
```