Update MacOS from keyLabel to characters

[danielroek]

Changed the MacOS implementation to use characters instead of keyLabel.

[shaxxx]

Since I don't have time (and this will not change in foreseeable future) to do a decent review I'm merging this.
Since package isn't at version 1.0 now, I believe that it's lesser evil than doing no updates.
And I'm currently without access to MacOS to actually test this.
Just ping me when you think it's time to publish package (now?)

Thank you for hard work.

[shaxxx]

@danielroek Is this ready to be published as a package?

[danielroek]

Yes, go ahead @shaxxx