Also cleans up repeated path options in the makefile, and cleans up
warnings where fennel-ls warns on itself.
There were some unused functions; I just put a _ before their name but
that might be a bit silly. Maybe they should be removed? Or just left alone?
Might be nice to be able to run make install as this is pretty
standard. For people who don't like sudo, they can set $PREFIX to a
user-writable location of their choice.
This makes the build itself a lot more portable. The executable of
course relies on lua being installed on the machine, but this will
nearly always be the case for a program used by Fennel developers.
Bonus: removes the direct use of the fennel.utils module which was
only used for the table? function and was causing a warning.
