Coding style clean up. Removing "this->"
	modified:   libmscore/accidental.cpp
	modified:   libmscore/ambitus.cpp
	modified:   libmscore/articulation.cpp
	modified:   libmscore/chord.cpp
	modified:   libmscore/chordline.cpp
	modified:   libmscore/chordrest.cpp
	modified:   libmscore/clef.cpp
	modified:   libmscore/element.cpp
	modified:   libmscore/hairpin.cpp
	modified:   libmscore/keysig.cpp
	modified:   libmscore/marker.cpp
	modified:   libmscore/measure.cpp
	modified:   libmscore/note.cpp
	modified:   libmscore/rest.cpp
	modified:   libmscore/tempotext.cpp
	modified:   libmscore/text.cpp
	modified:   libmscore/timesig.cpp
	modified:   libmscore/tremolo.cpp
	modified:   libmscore/volta.cpp
	modified:   mscore/scoreaccessibility.cpp