kismet: add support for older kernels that only have oldconfig and not olddefconfig

[paulgazz]

#238 adds kextractor support for linux 3.2, but kismet can't validate the unmet dependencies, because it uses make olddefconfig. make oldconfig works, but requires user input to set the defaults. A quick-and-dirty way is to do the following

yes '' | make oldconfig

with a timeout (in case there are options with no defaults). Update kismet to check the linux version and use this method instead of olddefconfig.

Related to #178 and #259