Due to setting `DESTDIR` *and* `exec_prefix` (defaulted to `$prefix`), binaries
ended up in `$out/$out/bin` instead of just $out/bin. Not setting `DESTDIR` and adapting
the `LIBDIR` patch a little fixes this issue.
* Remove package name
* Start with upper case letter
* Remove trailing period
Also reword some descriptions and move some long descriptions to
longDescription.
I'm not touching generated packages.
Also added the dependency on lablgtk, so that it builds the 'dgraph' module,
which is needed for packaging frama-c. This dependency can be made optional.
