Autocorrect the BEG() function

A balance formula should include the BEG() function, as so. Sometimes it is accidentally set to BEG(<name of balance>). While this is technically not wrong, it makes the formula longer than needed and can cause issues if the name of the balance is ever changed.

Openbox therefore offers to correct BEG(<name of balance>) to just BEG() – which means the same thing – if it finds it.