If..Else bugged when nested

[TehPers]

The following code should print "27", however it prints "2745": ?3{%3?0%4}!%5

This is caused by the internal ? failing and setting if_else to 0. When this occurs, the ! after the main conditional sees that ! is 0 and executes.

[aaronryank]

Mostly fixed in the latest commit; I still need to think of a good way to reset do_else if the command after an if is skipped is not else.