Add support for system installs

[lamawithonel]

It would be nice if this supported systems installs. Doing so could ease deployment.

By default the NC Class looks for the binaries in /usr/local/nc and the RPM installs them there. Converting the RPM is easy with Alien.

$ DEB_HOST_ARCH=i386 alien ncui-7.4R1.i386.rpm

The same thing could be achieved with a tarball. The only things missing are the icon and getx509certificate.sh script. These could be could be substituted with GPL versions, maybe.

I'm able to get this mostly working just by hard-coding $JNCPATH to /usr/local/nc. Because of the dependencies on the icon and script I still have to download the Jar file, but after this it works (nearly) without a hitch. The biggest problem is the lack of status; the system installed binaries log to /root/.juniper_networks/network_connect/<bin_name>.log.