Change docs license as requested in #6.
Allow configure options to be passed to autorelease.sh.

If you are on a system (like mine) where you need to pass options like
--with-readline=... to configure, then autorelease.sh would be a problem.
Now it takes the configure options as parameters to the script and passes them
on whenever configure is invoked, e.g.:

  ./autorelease.sh --with-readline=/usr/local/Cellar/readline/6.2.4
Update version to cgdb-0.6.7.