OR by AR charts by week and by season

odds_c_a_6wk_v7-8-13.py
- paired with updated ORgenerator.py, which
returns data structures with its functions
- draw OR by AR by week chart
- draw OR by AR by season chart
rm unneeded packages that were loaded

ORgenerator_v070813.py
- remove pylab and matplotlib and csv modules
return data structures instead of fill empty dicts

ORgenerator.py
- improved python practice by returning dicts
instead of filling already created empty dicts
within the function
- added to ORgen_wk to calculate total AR for
peak weeks
- added to ARdict_seas to calculate total AR
for peak weeks
- pairs only with odds_c_a_6wk_v7-8-13.py SDI
script; other main scripts need to be updated
to accommodate returns