* scm/paper.scm (layout-set-staff-size): use text-font-size in

* scm/paper.scm (layout-set-staff-size): use text-font-size in
dimension less points (ie. 12 = 12 point)

* lily/pango-select.cc (select_pango_font): use find_scaled_font().

* lily/all-font-metrics.cc (find_pango_font): set description_

* lily/pango-font.cc (text_stencil): export size as well.
(text_stencil): fix scaling and extents box.