lilyglyphs.sty: Do _not_ use fontspec

Responsibility to use fontspec is moved to the calling document.
This is because fontspec can be called with options, so hardcoding the call
into lilyglyphs.sty  could trigger option clashes

lilyglyphsStyle.sty now requires fontspec
Use \frenchspacing

According to Dave Bellows french spacing is now accepted in English texts too.
As it makes some things easier to enter I gladly apply that change