drivers: add virDomainCreateWithFlags if virDomainCreate exists

drivers: add virDomainCreateWithFlags if virDomainCreate exists

* src/esx/esx_driver.c (esxDomainCreate): Move guts...
(esxDomainCreateWithFlags): ...to new function.
(esxDriver): Trivially support the new API.
* src/lxc/lxc_driver.c (lxcDomainStart, lxcDomainStartWithFlags)
(lxcDriver): Likewise.
* src/opennebula/one_driver.c (oneDomainStart)
(oneDomainStartWithFlags, oneDriver): Likewise.
* src/openvz/openvz_driver.c (openvzDomainCreate)
(openvzDomainCreateWithFlags, openvzDriver): Likewise.
* src/qemu/qemu_driver.c (qemudDomainStart)
(qemudDomainStartWithFlags, qemuDriver): Likewise.
* src/test/test_driver.c (testDomainCreate)
(testDomainCreateWithFlags, testDriver): Likewise.
* src/uml/uml_driver.c (umlDomainStart, umlDomainStartWithFlags)
(umlDriver): Likewise.
* src/vbox/vbox_tmpl.c (vboxDomainCreate)
(vboxDomainCreateWithFlags, Driver): Likewise.
* src/xen/xen_driver.c (xenUnifiedDomainCreate)
(xenUnifiedDomainCreateWithFlags, xenUnifiedDriver): Likewise.
* src/xenapi/xenapi_driver.c (xenapiDomainCreate)
(xenapiDomainCreateWithFlags, xenapiDriver): Likewise.