Replace Funding Period admin page with Fiscal Year page

[gluxon]

• Associate Budget to fiscal years rather than FundingPeriod.
• Create a new many-to-many relationship between funding periods and fiscal years. A good name might be BudgetAllocation. Give it an amount field which will be the amount of the budget allocated to that funding period.
  • Think about whether it makes sense for Budget to have an amount field itself. I believe in all scenarios the budget's amount will just be the sum of all amounts allocated to a funding period.