Various clean ups in documentation and code
Various clean ups in documentation and code

This commit improves the following items:
 - Remove the 'match' functionality, this can now be achieve by using the `fail` module together with `only_if` after running the `hpilo_facts` module. Since this gives more functionality, e.g. comparing server names, but also serial numbers or uuids with other inventory information, this is prefered. An example is added to show how this is achieved.
 - Clean up all C() calls in documentation
 - Added state=poweroff in order to power off a server. The use-case is here that in general we do not want to provision systems that are already running (this enforcement can be disabled using force=yes) but for test systems we should be able to power them off so we can start the normal provisioning process. (We could also force boot them, but that's less elegant)
 - The module now correctly indicates when something has changed. So if a server is powered off that was not off already, this is indicated, or when media boot-settings have been changed, this is also correctly indicated. Previously every call to hpilo_boot was (incorrectly) considered a change.

thaim/ansible,thaim/ansible