update install path
update install path

Hello,

I see that one can specify the install path with
`make -e INSTALLDIR=/usr/local/bin` but I think it's far better if
`/usr/local/bin/` is the default and anything else can be specified.
If one were to  `sudo make install`, the file will end up in /root/ and you
certainly don't want root priv to execute the file.

Thanks for the consideration!
olorin/miller,0-wiz-0/miller,svacha/miller,olorin/miller,svacha/miller,svacha/miller,0-wiz-0/miller,olorin/miller,olorin/miller,0-wiz-0/miller,svacha/miller,svacha/miller,0-wiz-0/miller,0-wiz-0/miller,olorin/miller,svacha/miller,olorin/miller,0-wiz-0/miller,0-wiz-0/miller,0-wiz-0/miller,olorin/miller,olorin/miller,svacha/miller,svacha/miller