Option to remove empty pages?

[YbCl3]

Depending on the settings cropping an empty page doesn't always really make much sense, resulting in things like tiny square pages, or even errors that leave the page uncropped because it would have 0 size.

I don't know enough about how PDFs work to know if this would be a sensible thing to add, or if it would be too different from/outside the scope of the normal cropping this tool does, but it seems to me like it would be useful to have the option to completely remove the empty pages when cropping.

[abarker]

I try to keep the scope of the program to cropping. If the empty pages are causing errors, though, that seems like a bug. That case could at least have some minimum size to avoid errors. I'll consider the option to drop pages below some threshold size.