Remove useless stuff

No idea why this is here, probably some copy-paste gone wrong
while I was still trying to understand the Autotools...
Move the setup tool to bindir

This is a user program, as such it really should be installed in her
PATH, so she can execute it.
Move the engine script to pkglibexecdir

First, this sets libexecdir as $(prefix)/lib, because really, that's
where this kind of things should be.

However, to avoid polluting e.g /usr/lib, we now install in our own
sub-directory.