copyright year in source file headers
support the dotted path notation for \override and \revert
make sure that after a dot in an override or revert command just 1 name may occur

otherwise following notes would be erroneously seen as property names
allow separate context.grob and property paths

todo: support that also for \revert; improve complete path parsing
todo: improve \revert path parsing
Fix for Issue #336
Clean-up, also fixes Issue #331
correcly parse/highlight all possible \revert argument variants
remove EqualSignSetOverride
allow direct decimal values after the "=" in \set and \override
add NullVoice
handle \tweak in the new syntax
add new 2.18 commands that are mentioned in the changes
parse \accidentalStyle
parse \alterBroken
add \undo, make \undo, \hide and \omit keywords
be a bit more tolerant at the top level
highlight context- and grob names in with, layout and midi
autocomplete accidentalstyle
Merge pull request #339 from PeterBjuhr/master

Fixes MusicXML export