Replace -TSDZ for -ten by just -Z

[Willem3141]

This was a nice idea, but -TSDZ is really horrible to stroke. I just got another idea, which is to use just -Z for this.

For words that do not have any consonant before the -t, this doesn't really create any conflicts, and can even be implemented by an orthography rule. (Special cases: weeën, zeeën.)

Some other words do get a conflict (lachen / lachten), but in that case it's usually a past tense, and the system doesn't support doing past tense forms in one stroke anyway.