some cleanup in number box node
add contextual menu for selection
fix typo in class name
add user function factory
implement user function creation
allow nested function calls
fix 'undefined' class adding
make subeditors larger when maximised
add events for subeditors
fix node destruction when deleting functions
hook f key to create function + implement node deletion in subeditors
fix wire dragging in subeditors
encapsulate wire position calculations in BaseNode methods
add default argument for  user functions
save and restore wires connected to arguments in subeditors
when deleting function, delete its nodes in all subeditors