Add vm/show_list post route for vm list paging controls

https://bugzilla.redhat.com/show_bug.cgi?id=1128252
New paging_controls_url helper to handle extra URL parms

https://bugzilla.redhat.com/show_bug.cgi?id=1128244
Merge pull request #389 from dclarizio/paging_control_links_need_chart_set_info

Paging control links need chart set info and new route
ManageIQ model infrastructure changes for vendor specific methods.

Changed Method class schema to add vendor specific methods and
relationships.
Added red hat and vmware pre provision and customize request methods.
Changed customizerequest and preprovision instances to call vendor
specific methods.
Changed VMProvision_Template and VMProvision_VM schema default values
to pass vendor name as message to pre provision and customizerequest.
ManageIQ model cloud changes for vendor specific methods.

Changed Method class schema to add vendor specific methods and
relationships.
Added amazon and openstack pre provision and customize request methods.
Changed customizerequest and preprovision instances to call vendor
specific methods.
Changed VMProvision_Template and VMProvision_VM schema default values
to pass vendor name as message to pre provision and customizerequest.
more changes