Merge remote-tracking branch 'upstream/master' into zoltan-dev
plain staff test to test no connector on a single staff
redefine section plane: a plain mei can contain multiple alternative versions.
fixed: problem when trying to replace an app that isn't in the sectionview_score
meilib.js: define how to remove items from the section plane.
When an item is removed it si replaced with the one that included by initSecionPlane;
Merge remote-tracking branch 'aerhard/master' into zoltan-dev

Conflicts:
	src/meilib.js
Merge remote-tracking branch 'upstream/master' into zoltan-dev
fixed: default reading/choice don't get inserted to initial plain mei
added test for no margin layouts;

fixed some wrong indentation
added function to get area of all rendered measure staves
bug fix proposal (issue #26)
Merge pull request #25 from zolaemil/zoltan-dev

meilib.js improvements
Merge pull request #29 from aerhard/measure_zero_fix

bug fix proposal (issue #26)