Cashculator integration

[hsoft]

From GS

1. The user imports its financial data in moneyGuru and keeps it
   up-to-date in moneyGuru.
2. One day, they feel the need to do some budgeting.
3. They use a feature in moneyGuru called "Create Budgets with Cashculator".
4. moneyGuru creates/modify its own Cashculator database, adds all
   Income/Expenses accounts to the cashculator file and set numbers
   according to past transactions and scheduled ones.
5. The user plays with Cashculator, and end up designing a budget they
   want to stick to.
6. They use "Import Budgets from Cashculator" and then moneyGuru reads
   its cashculator file, and modifies its budget items according to what
   has been designed in Cashculator.

[hsoft]

The feature has been scaled back a little bit. For now, only data exports are available.