Disable keyboard shortcuts when text input is focused

[Luke Bayes]

Hey Folks,

First off, thank you so much for all your hard work on this project, it's really incredible what you've been able to accomplish and I'm truly grateful!

I've been lurking in the discussion group for awhile, but I'm a relatively new user of the software, so please let me know if I'm missing something here.

I ran into an issue where I'm editing text fields in the GUI and if I press CTRL+ARROW or CTRL+SHIFT+ARROW (common keyboard shortcuts to select text), my machine head jogs around, potentially damaging it or other things in my work area.

Even though it's been years since I got Java on my skin, I went ahead and threw together a branch to see what a fix might look like.

Here is a diff

It builds and runs, and all tests still pass, but I have not introduced new tests for this patch.

Before I dig much further, I wanted to check in with folks and get your thoughts on this change.

Any feedback is welcomed.

Thanks again!

Luke Bayes