Fix uninstall

- Remove shared lib link and deprecated.3 man page
- Handle removal of targets that are referred to with a path
Fix install on OSX

Use parameters common to GNU and BSD flavors of `install' and `cp' utilities.
Make install more flexible by removing `usr' from fix install path

- Allow specifying an install path that does not contain a `usr' directory
- If not provided, install path still default to `/usr'