Fix Resample Resolution

[varyg1001]

I'm using the latest "full" release, so not sure if this already fixed in later commit.

Can be fixed to also update LayoutRes X/Y if presented in the file, when the subtitle is resized?

[arch1t3cht]

Handling LayoutRes is the next high priority feature. The problem is that it's a bit tricky to properly implement it and handle all possible cases (see this discussion libass/libass#734), and as you can probably see I have a lot less time for Aegisub work right now. But I'll work on it as soon as I can.