DrForr

A long time coming, this looks along /usr/lib64 and /lib/x86_64-linux-gnu for existing libreadline.so.* libraries, otherwise assumes v7. I'll add more directories as I find them, and make sure that it looks recursively in /lib if all else fails as part of the next release. I'll be adding comments to the GitHub issues shortly, as it should address most of the existing problems.