Remove black borders and resize level in an easier way [SUGGESTION] [EDITOR]

[Wafflem]

BitBucket: https://bitbucket.org/namida42/neolemmixplayer/issues/34/trim-unused-space-function

As everyone knows, I'm currently helping Nepster convert a lot of the DOS/Lemmix levels into NeoLemmix.

One of the changes to the Lemmix levels involves, of course, removing all unused space. However, to do that, I have to shift the level and then resize the level size by manually entering the number. Sometimes, I end up cutting out part of the level, sometimes when I shift the level to the left it ends up over the left border. It's basically trial-and-error, and this can be inconvenient.

Is there a way you can add a function in the editor so that any unused space is automatically removed and the level is automatically adjusted to fit within the new size without me having to do this all by myself? This will also be helpful for those who wish to convert their Lemmix/Lemmini/SuperLemmini levels to NeoLemmix. Not sure if I explained clearly.