Make origins instances of a georeference class 
(like class point from GPScape).
It would conatin multiple representation, projections and code for adding itself to e.g. NetCDF files.
 	

	
	
Tagged regions, edges etc should be done in terms of set-theory,
so that each tag maps e.g. to a list of indices.	


#DONE AND OBSOLETE	
#Migrate code from domain.py so as much as possible is
#done in terms of the consecutive arrays. 
#We can then destroy the Python objects after everything has been setup,
#in order to conserved memory.