EventLink.params contains pitch name, slur nesting level, and/or hairpin parameters
in StaffInfo.js now new_staffDef spelled correctly.
start new system after <sb/>
full scoreDef in MeterChange test
added tests for changing staffDef; some bug fixes
system breaks: calculate measure width according to number of measure in the system.
@tie @slur handle system breaks
FIXED: terminate tie disregards octave)
added tests for ties in multiple layers, and witin chords
Merge branch 'master' of https://github.com/zolaemil/MEItoVexFlow
Merge branch 'system_break'

Conflicts:
	tests/tests.html