Modifications in Budget

closes #460 (closed)
Profit & Loss Budget:
Budget module is modified as per the details in above issue. Now Expense and Sales budgets have been replaced with a new budget type - Profit & Loss.
It is similar to Profit & loss report. Only difference is it will have budget amounts against each account and their variance is calculated in budget report.
Accounts which are consider in this budget are from Direct and Indirect Expense and Incomes groups.
Formulas used in the P&L budget report are:
variance for income = actual - budget
variance for expense = budget - actual
net profit = income - expense (for both budgeted and actual)
variance net profit = actual - budget

Cash Budget:
Now in cash budget will consider all accounts. Users can add budget amoount against each account instead of Bank and Cash subgroup accounts.
Considered all accounts involved in transactions with Cash and Bank accounts.
Budget amount for an account will be considered as 0.00 if none is provided. Their are opening and closing fields in report which having accounts from Cash and Bank subgroups.
Inflow field will consider accounts from Direct,Indirect Income and Current Assets groups.
Outflow field will consider accounts from Direct,Indirect Expense and Current Liabilities groups.
variance for inflow = actual - budget
variance for outflow = budget - actual variance in percent = (100 * variance) / budget Closing accounts budget = opening of accounts + Total Inflow - Total Outflow