Allow selection of multiple files at once
This changes the function of the "+"-button in the Manage MoCap-dialog. It now opens a file dialog with the possibility to select more than one file.
In future we might want to expand this, since now every file is imported with the default values, i.e. as XSens C3D. But regarding that we currently only have those, I do not think that this is critical.
Closes #201 (closed)
Edited by d.kilic