Merge pull request #3 from zolaemil/master

Massaging all reconstructions, variants and emendations
Merge pull request #6 from zolaemil/master

minor changes
Merge https://github.com/DuChemin/MEIMassaging
added test case for reconstruction and variant for the same voice
changed name of test file to standard Du Chemin name
test case with a single variant source
fixed parameters for test case DC0221
updated MEI test files that are generated by Sibelius plugin

revised passing test cases (marked TCs causing segfault)
adjusted a test case to test NCName correction
Convert Source IDs into valid NCName strings
Merge branch 'ncname'
ignore database file