New installation of openhabian on a clean SD card on the rPi2 (installs under Debian Jessie) works with Razberry card 
after :
adding -Dgnu.io.rxtx.SerialPorts=/dev/ttyAMA0" to setenv and
sudo chmod 666 /dev/ttyAMA0
which gives
ls -la /dev/ttyAMA0
crw-rw-rw- 1 root tty 204, 64 Jan 11 18:24 /dev/ttyAMA0
Thanks to all of those involved over at openHABian hassle-free openHAB Setup in putting openhabian together. The installation works very smoothly.
So this may support the case that NrjavaSerial 3.12 does not work under Debian Wheezy - at least on rPi2 devices whereas the previous version 3.9 worked fine. Maybe Wheezy does not support a required dependency of nrjavaserial library.