Release of VPL 3.4.2

This is a bug-fix release of VPL. 3.4.1.

Prerequisites

Supports the General Data Protection Regulation (GDPR)
To protect you from accidentally lost work when saving files, the system now asks for confirmation when you want to save a submission or configuration older than the current saved.
Adds Chinese (simplified) translation thanks to the Computer Science Education group of Beijing Technology and Business University
To improve the identification of directories when downloading student's submissions add the username field to the user directory name.

Icons have been added to easier access to menus and options.
Users can select themes for the editor and terminal.
Terminal can be size reduced.
Edition is available when running.
The "Submissions list" now includes an "action menu" to the right of each row. The "action menu" of the heading allows accessing "Assessment report", "Download submissions", etc. The "action menu" of each submission allows access to "Submission view", "Previous submissions list", "Grade" and "Copy submission".
The variation edition interface now allows using the HTML editor.
Charts are now using the new Moodle API.

Adds support for Kotlin adding a default run script. Kotlin is detected when using files with the kt file extension. Notice that the Jail servers do not support Snap packages, you must install Kotlin compiler manually or use jail server installer 2.7 or higher.
Adds support for Minizinc adding a default run script. Minizinc is detected when using files with the mzn file extension.
Adds support for Groovy adding a default run script. Groovy is detected when using files with the groovy file extension.
Adds support for error messages from PHP and Perl.
Adds new indexes to speedup DB access.
Adds 'dll' extension to the list of binary file extensions.

Fixes spurious problem loading VNC code that avoids showing the editor.
Reverts to previous behavior allowing non-alphanum chars in variation identification field.
Fixes bug in variations logging
Fixes import and drag and drop files on the editor

Fixes a bug that prevents teachers from downloading all students' submissions as a zip file.

The teachers with privileges can see the Jail server URL path, now the path is not shown.
Detects if ws/wss protocol is not available at jail server to selects the correct one.
Fixes error deleting variations.
Avoid assigning variations on group activity.

VPL 3.4.1 is fully compatible with previous versions.
Notice that in some cases, after the upgrade, for a while the clients can use their cached JavaScript code instead of the new one. To resolve this issue you must hold the Ctrl key and click the Reload button on the navigation toolbar.