Cope with the morphing weight values

Use CSV as the format of the file containing the morphing weight values (the α values). The values in this CSV file must be separated by commas and must contain no header. The number of rows in this CSV file must be equal to the number of markers (which must be the same for the two signals) and the number of columns must be equal to the number of desired morphed output signals.

The file can be uploaded only after one of the markers files has been updated. Otherwise, the buttons must be deactivated.

When this file is uploaded to the frontend, the following checks must be made:

• The number of lines is equal to the number of markers
• The values are in the interval [0, 1]

A possible library for reading CSV files is jquery-csv.