When running "make clean" in libgrapheme, do so in the $(distdir) target, and not the $(topsrc)/libgrapheme target, as by the time dist-hook runs, the files have already been prepared in $(distdir).

Make sure we clean out any unwanted files in libgrapheme/ when creeating a release tarball, as we don't want such files present.

When making release tarballs, ensure we also include libgrapheme in case that's not available system-wide.

This leaves the room open to further improvements and tries to keep it apart from the UI itself.

fixes a regression where the text inputted via ui_read() can't be edited.