Have rewritten and cleaned up the classes for storing and computing modular forms.
The structure is:
 - compmf/filesdb.py  -- contains classes for storing and loading modular forms from files
 - compmf/compute.py  -- contain the class we use to do tha actual computations of modular forms (and save into files)
 - compmf/mongodb.py  -- contains the new class 'CompMF' which should be used to compute modular forms and inserting into mongodb (optionally get records from files and insert records into files)
The new module 'compmf' contains all relevant routines for computing and storing modular forms.
The character conversion routines are moved to the compmf module (although in this commit they are actually present in both modules)
Changed all imports to imprt the character conversions from compmf