JavaScript compilation update

update the build script to compile both square-note and staffless
neumes.
Organize MEI directory

create subdirectories for each document type: square note notation and
staffless neume notation. A different template for each document type
sets the parameters of neon to allow the editing of the different
documents. Can also upload files of each document type and they are
placed in the appropriate directories. Removed explicit setting of the
MEI document backup directory in the configuration file. Now, the backup
file is mandatorily called "backup".

Also changed revert to a post request. Fixes #77