[IATI/IATI-Dashboard#218] Remove forwardlooking fallback

(to planned disbursements)
[IATI/IATI-Dashboard#218] Add new forward looking numerator and denominator calculations
[IATI/IATI-Dashboard#218] Update budget_year function to reflect Bill's recent comment

https://github.com/IATI/IATI-Dashboard/issues/218#issuecomment-60225775
[IATI/IATI-Dashboard#244] Calculate forward looking calculations for lowest hierarchy
Include all end dates and ignore invalid iso dates
[#43] Use correct if statement for skipping commits
[IATI/IATI-Dashboard#234] Update Stats code for 1.051
Fix Decimal support in gitaggregate-publisher
[IATI/IATI-Dashboard#244] Treat no hierachy attribute as hierarchy 1
[IATI/IATI-Dashboard#265] Activities with no end date are current
Add missing .py extensions in README
tmp
tmp2
tmp3