api: add format flag to <storage_domain/> as a DELETE param
api: add format flag to <storage_domain/> as a DELETE param

https://fedorahosted.org/rhevm-api/ticket/172

Add a flag to <storage_domain/> to allow the client to request that
a storage domain is formatted when it is deleted:

e.g.

  -> DELETE /api/storagedomains/xyz HTTP/1.1
  -> Content-Type: application/xml
  ->
  -> <storage_domain>
  ->   <host id="0"/>
  ->   <format>true</format>
  -> </storage_domain>

  <- 204 No Content

Acked-by: Mark McLoughlin <c437454578aa740e24bc1bc37b06380de7125486@redhat.com>

markmc/rhevm-api,markmc/rhevm-api,markmc/rhevm-api