Warn on % input

[cassidyjames]

To solve issues like #44, we could throw an infobar letting the user know that % is ambiguous, and to try multiplying by a decimal instead to be more clear.

[cassidyjames]

An alternative: we could just not accept % as valid input due to the ambiguity. Probably simpler, but might be less clear.

[jeremypw]

@cassidyjames Does the linked PR make any sense at all as a way of addressing this issue? Or would throwing a dialog or ignoring as invalid be preferable?

[cassidyjames]

@jeremypw I think the linked PR tries to invent new operators which are going to be unfamiliar to most, and still ambiguous if you don't know how they work. I would prefer just not accepting % inputs, honestly.

[jeremypw]

No problem - I'll close that PR.