Created a provision request cancel message to replace the generic "Add a new ____ cancelled by the user" message used by the prov_edit method in miq_request_methods.rb

New provision cancel message will be displayed after the cancellation of a host provision or vm provision.

https://bugzilla.redhat.com/show_bug.cgi?id=1114143
Merge pull request #406 from jcarter12/add_host_provision_cancel_message

BZ 1114143 Added host provisioning cancel message when cancelled by the user