Simplify binding
Add a basic Makefile for byte compilation
Use find-library-name to find feature source file

Remove s.el dependency, as it is superfluous now, and require find-func
instead, which provides find-library-name.  Also signal errors now, if
the library was not found.
Simplify search for defining library

Also signal an error now, if the defining library was not found.
Use EPL to retrieve package information
Add tests for pkg-info
Don't pretend to extract versions from files