Several small updates
- Better error-handling for Demo Mode JS methods
- Update a method that returns a unique selector for JS calls
- Update .gitignore and the "sbase mkdir DIR" test directory generator
- Add "sbase record": Calls "sbase mkrec" if has args, or "sbase recorder" if no args
- Add "--overwrite" option when calling "sbase mkrec FILE"
- Recorder: Display error message if naming a file "abc.py" (reserved Python module)
- Refresh Python dependencies
- Update example tests