[libvirt] ESX [04/12]: Add tests for the VMX to/from domain XML mapping

* tests/.gitignore: ignore new test binaries * tests/Makefile.am: add new tests * tests/esxutilstest.c: test esxVMX_IndexToDiskName() * tests/vmx2xmldata/*: config files for the VMX to domain XML test * tests/vmx2xmltest.c: test the VMX to domain XML mapping * tests/xml2vmxdata/*: config files for the domain XML to VMX test * tests/xml2vmxtest.c: test the domain XML to VMX mapping