Feature Request: Allow currency exchange transactions

[belidzs]

This would be useful on trips which include multiple countries.

Expenses and balances can be difficult to track when there are multiple currencies involved. For example on a trip to Japan I may be owed 100 USD for booking some accommodations from home and owing 10.000 JPY for my expenses covered by friends abroad. It's difficult to tell whether my balance is greater than zero or not. A relatively simple solution for this would be providing a view which dynamically converts all balances to a specified base currency on the fly, but that's not very robust due to the changing nature of rates.

Instead, I recommend implementing manual settlement transactions which convert one currency to another. The currency rate should be provided by the user (and maybe suggested by the application).

In the example above once we leave Japan, we could convert the remaining balance of JPY to USD, so +100 USD, -10.000 JPY would become +32 USD, 0 JPY with a conversion rate of 146 JPY/USD (the settlement transaction would be -68 USD, +10.000 JPY)

[KMKoushik]

this a nice feature, but i don't think i have the time to implement this now. might need some help from the community!