Clean-up of mscore font

- Glyphs present in both legacy Emmentaler and SMuFL encoding have been unified: the Emmentaler code point now contains a reference to the SMuFL code point
- Large parentheses (U+E094, U+E095) changed to use the same graphic style of other Emmentaler parentheses (metrics not changed)
- Intersecting path in 128th rest (U+E10D) corrected
- Wrong path direction in U+E180 corrected
- Intersecting path in "volumeswell" (U+E845) corrected (required to separate a few FU the two parts, metrics unchanged)
- "wigglesawtooth" and "wigglesawtoothwide" (U+EABB, U+EABC) centred in glyph width
- All recently added or modified glyphs now pass validation
Fix missing "FullName" line in .sfd source
Changed "Base file name" to the file name actually used.
Added README.md file for "fonts" directory
Merge pull request #1147 from mgavioli/mscore_font_cleanup

Clean-up of mscore font