Qt4Macros: improve basename extraction in QT4_ADD_DBUS_INTERFACES

-convert the filename to lowercase before the extraction, this allows this to
 work even if the filename as uppercase ".XML" extension
-use get_filename_component(... NAME) to strip the path

Modules/Qt4Macros.cmake

@@ -258,9 +258,10 @@ ENDMACRO(QT4_ADD_DBUS_INTERFACE)
 MACRO(QT4_ADD_DBUS_INTERFACES _sources)
   FOREACH (_current_FILE ${ARGN})
     GET_FILENAME_COMPONENT(_infile ${_current_FILE} ABSOLUTE)
+    GET_FILENAME_COMPONENT(_basename ${_current_FILE} NAME)
     # get the part before the ".xml" suffix
-    STRING(REGEX REPLACE "(.*[/\\.])?([^\\.]+)\\.xml" "\\2" _basename ${_current_FILE})
     STRING(TOLOWER ${_basename} _basename)
+    STRING(REGEX REPLACE "(.*\\.)?([^\\.]+)\\.xml" "\\2" _basename ${_basename})
     QT4_ADD_DBUS_INTERFACE(${_sources} ${_infile} ${_basename}interface)
   ENDFOREACH (_current_FILE)
 ENDMACRO(QT4_ADD_DBUS_INTERFACES)