Unlink references in mscore font

Glyphs with references in .TTF font are rendered with errors under Windows. This patch replaces the clef+numbers glyphs (which were using references to the individual components) with actual outlines.

In addition, position of numbers on bass clef have been improved (better balanced above and below).
Merge pull request #549 from mgavioli/Unlink_refs_in_mscore_font

Unlink references in mscore font