Revision 2301

Changed all class functions. Now all metadata will handle by the function and its not needed to initialize it from outside. Therefor the associated mapobj will be stored in the Metadata Object. So we can use thespecial functions from the associated mapobj to get the Metadata. Therefor all initialization code for the metadata is removed from the other classes.
(MF_Layer): Added a function to get the metadata object.
(MF_Map): Added a function to set the mappath, the path where the mapfile ist stored.