Update test suite accordingly.

Also don't abuse the disk driver name to specify the SCSI controller
model anymore:

  <driver name='buslogic'/>

Use the newly added model attribute of the controller element for this:

  <controller type='scsi' index='0' model='buslogic'/>

The disk driver name approach is deprecated now, but still works for
backward compatibility reasons.

Update the documentation and tests accordingly.

Fix usage of the words controller and id in the VMX handling code. Use
controller, bus and unit properly.

A given domain XML gets converted to a VMX config, uploaded to the host
and registered as new virtual machine.

* src/esx/esx_driver.c: refactor datastore related path parsing into
  esxUtil_ParseDatastoreRelatedPath()
* src/esx/esx_util.[ch]: add esxUtil_ParseDatastoreRelatedPath()
* src/esx/esx_vi.[ch]: add esxVI_Context_UploadFile(), add datastores to
  the traversal in esxVI_BuildFullTraversalSpecList(), add
  esxVI_LookupDatastoreByName()
* src/esx/esx_vi_methods.[ch]: add esxVI_RegisterVM_Task()
* src/esx/esx_vi_types.c: make some error message more verbose
* src/esx/esx_vmx.[ch]: add esxVMX_AbsolutePathToDatastoreRelatedPath()
  to convert a path into a datastore related path, add esxVMX_ParseFileName()
  to convert from VMX path format to domain XML path format, extend the other
  parsing function to be datastore aware, add esxVMX_FormatFileName() to
  convert from domain XML path format to VMX path format, fix VMX ethernet
  entry formating
* tests/esxutilstest.c: add test for esxUtil_ParseDatastoreRelatedPath()
* tests/vmx2xmldata/*: update domain XML files to use datastore related paths
* tests/xml2vmxdata/*: update domain XML files to use datastore related paths,
  update VMX files to use absolute paths

* 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