Fixed issues found by Travis 3
Fixed issues found by Travis 3

grame-cncm/libmusicxml,dfober/libmusicxml,grame-cncm/libmusicxml,grame-cncm/libmusicxml,arshiacont/libmusicxml,grame-cncm/libmusicxml,arshiacont/libmusicxml,arshiacont/libmusicxml,dfober/libmusicxml,arshiacont/libmusicxml,dfober/libmusicxml,grame-cncm/libmusicxml,grame-cncm/libmusicxml,arshiacont/libmusicxml,dfober/libmusicxml