Bring back productivity for QWERTZ keyboards

Patch set - 1
http://review.cyanogenmod.com/#/c/24532/1
changed the productivity for QWERTZ keyboards in a bad way
because rowkeys_qwerty2.xml was also used as 2nd QWERTZ row.

For de_DE 'ä' and 'ß' are far more usual then '@' and '#'
Also exchange '$' with '€'

I hope this doesn't break other locales using QWERTZ

Patch set -2
Also use 'rowkeys_qwertz2.xml' for the 600dp and 768dp layouts
and enable AdditionalMoreKeys for row 1 on QWERTZ keyboards

Change-Id: I22d80778b56403c5d56a6a0e19a8393bbdcbeb1b