New character set behavior

We've released a new update that changes how you create custom presets. You can now write whatever you like in the character-set input and duplicated characters will just be ignored:

You can also click the "Remove duplicates" button to clean up the input:

Previously you wouldn't be able to type in a duplicated character which, to be honest, was a bit annoying.

Removed some bugs

We've also fixed two bugs:

- when typing in a character in the middle of the character set input the cursor will behave as expected (previously it would move to the end)

- new update notification will now show up properly whenever we add something cool (previously it just wouldn't)