Parameter to save running VM's configuration

When save_config_on_stop_default is set to 1 the RA will dump the running VM's config to "config" during resource stop.
moved save_config to a new function, changed save_config_on_stop to boolean

* moved save_config to a new function
* changed save_config_on_stop to boolean
* set default of save_config_on_stop to false
* changed condition to use ocf_is_true
Merge pull request #446 from oshikore/master

Parameter to save running VM's configuration