add ability to remove sketches from server-side program
add ability to remove sketches from server-side program

semmypurewal/processing.js-ide,semmypurewal/processing.js-ide,semmypurewal/processing.js-ide,semmypurewal/processing.js-ide,semmypurewal/processing.js-ide,semmypurewal/processing.js-ide,semmypurewal/processing.js-ide,semmypurewal/processing.js-ide,semmypurewal/processing.js-ide,semmypurewal/processing.js-ide