If book has budgets, and GNC_FEATURE_BUDGET_UNREVERSED isn't set,
check and fix budget amount signs. Previously budgets were created
with assumption that sign reversal was set to credit amounts. A
heuristic approach is used:
- if budgeted expense is negative, conclude sign reversal is
"Income and Expense"
- if budgeted liability is positive, conclude sign reversal is
"None"
- otherwise conclude sign reversal is "Credit Accounts"
The above is calibrated to (hopefully) prefer sign reversal of Credit
Accounts.
