Revision 2319

Added a Class and a function to show the Annotation layer in thuban. The layer don't do anything.
Its only to show the layer. Necessary to save the layer order.
Added a funtion to import only layers to thuban and not the other settings like projection or scalebar.
Moved the _has_umn_mapobj function and the create_new_mapfile functions from mf_handle.py to mf_import.py.
(select_layer2import): Moved the code for showing the number of layer from import_mapfile to this function.