Version items are now fake strings, as I still miss the code
that reads if from the device.  But they work, and the mib is
updated:

   tornado% snmpwalk -c public -v 2c -m +`pwd`/WR-SWITCH-MIB.txt wrs \
            .1.3.6.1.4.1.96.100.4
   WR-SWITCH-MIB::wrsVersionSw.0 = STRING:  fake-v4.0-rc1
   WR-SWITCH-MIB::wrsVersionGw1.0 = STRING: fake-7cce708
   WR-SWITCH-MIB::wrsVersionGw2.0 = STRING: fake-5118070
   WR-SWITCH-MIB::wrsVersionGw3.0 = STRING: fake-7efeb16
   WR-SWITCH-MIB::wrsVersionHw1.0 = STRING: fake-3.30
   WR-SWITCH-MIB::wrsVersionHw2.0 = STRING: fake-LX240T
Signed-off-by: Alessandro Rubini <rubini@gnudd.com>