autofind tun.ko driver and save into prefs about android-openvpn-settings HOT 5 OPEN

See also:
http://code.google.com/p/android-openvpn-settings/source/detail?r=86651cf1503147
eb8eef77070dc9a995dba71767

I like the idea, but i would rather use a pure java solution in this case.
IMHO it would be better not to rely on an external process.

I already implemented a similar method in OpenVPN-Installer which we could use 
(Need
to add the recursion, but that's trivial).
Code is here:
http://code.google.com/p/android-openvpn-installer/source/browse/src/de/schaeuff
elhut/android/openvpn/installer/OpenVPNInstaller.java#440

The find process should run in int's own thread, while a progress bar is shown 
to the
user (even if scanning is be quick). Code for that might also be found in the
OpenVPN-Installer source.