NAME
	mapr_mapping - map a mapping through a function

SYNTAX
	mapping map_mapping(mapping map,function fun,mixed args...);
	mapping map_mapping(mapping map,string fun,mixed args...);
	mapping map_mapping(mapping map,-1,mixed args...);

DESCRIPTION
	Works exactly like map_array, but works on a mapping.
	map_array(X,Y,Z) is equivialent to:
	mkmapping(m_indices(X),map_array(m_values(X),Y,Z))
	but faster....

SEE ALSO
	map_array, filter_mapping