ktest: Add standalone config-bisect.pl program

ktest: Add standalone config-bisect.pl program

Started working on a stand alone program that can do a config bisect. It is
based on the config bisect code of ktest.pl. Instead of needing all the
infrastructure of ktest.pl, all that is required for config-bisect.pl is two
config files. One that works, and one that does not. The goal is to pass in
the two files, and it will create a new "good" and a new "bad" config file
based on input from the user. After several iterations (calls to this
program), it will eventually end with a minimum config value that allows one
config to work and the other config to break.

The program uses a technique that takes the good config and then makes half
of the configs that differ from the bad config just like the bad config.
The code will use make oldconfig to make sure the configs that are set are
not all converted back due to incorrect dependencies on other configs set in
the bad config but not in the new test config.

This is still a work in progress, but as it was written while I was working
at Red Hat, I want this code to be submitted as such.

Signed-off-by: Steven Rostedt (Red Hat) <rostedt@goodmis.org>