adding libmei files
Add newly generated libmei that makes verovio compile again
Adjusting emscripten Makefiles
removing old Common att class
updating libmei
Merge pull request #27 from rism-ch/experimental-libmei

Merging experimental libmei to master
Update README.md
Update README.md
Ignoring and logging PPQ duration values
Adding MeterSig class based on LibMEI att class
Adding meterSig element and in score/staffDef
Renaming KeySignature to KeySig
Read intermediate scoreDefs (basic and only for score-based MEI)
adding all-pages options to command-line tool
Fix in all-pages
Another fix in --all-pages
Adding page number check in command-line
Switching to libmei att for more elements
Adding missing header files
AttColored and AttNoteLogMensural for Note