ORA-4.0.0

This release is based on the cross compiler resources tag 20

New Features

#785 As a teacher I would like to create groups for my classes to be better prepared in the lessons
#874 Debugger for Robot Simulations
#747 Configuration for Mbed - Calliope and Micro:Bit
#856 Feedback button
#880 Add color sensor TCS34725FN to Calliope mini
#878 Add environmental sensor BME680 to sensebox
#549 Add control for internal RGB Led, Arduino Uno Wifi Rev2
#873 Calliope: String / Char conversion (cast) to float / int and vice versa
#854 Direct link to the tutorials
#752 Gallery improvements
#844 Documentation of the JSON data used by our REST services

Bug Fixes

#881 Program disappears for server errors
#872 Miscellaneous problems with sensebox blocks, only labeling
#871 Sensebox RGB Led not working
#870 Input field for "WLAN credentials ..." does not allow "Umlaute"
#866 Blockly build fails for some time
#857 Calliope mini firmware "reset to factory default"
#849 Arduino: "Wait for" block is broken when plus icon is clicked
#848 Arduino: Multiple problems with the timer
#544 Arduino: some wait until sensors are not associated with configuration blocks
#710 Remove jquery-cookie library