* First microbit gui tests
* Fixed JSONRPC inheritance. Renamed ScratchBLE/ScratchBT files. Removed ScratchBT test code from Microbit extension. Renamed addLine to log.
* Fixed log comments. Removed addLine from Microbit.
* Adding auto-connect to Microbit at extension loading. Adding hack for displayText block to Scratch-Link.
* Resolved merge conflicts and brought in latest microbit extension example code.
* Updated microbit write tests for displayText and displaySymbol blocks. Some linting.
* Some linting and adding of BLE Characteristic consts.
* Linting fixes.
* Moving micro:bit device connection code all to the MicroBit class, decoupling Scratch3MicroBitBlocks from connection code.
* Removing old disconenct handlers from MicroBit class. Moved service into new BLEUUID data structure.
* Renamed _write to _send. Moved all BLE encoding concerns to the _send method.
* Using the util log. Some linting.
* Added _read method to MicroBit class. Renamed _send to _write.
* Some linting and formatting comments.
* First pass at peripheral chooser pattern for ScratchBLE.
* Testing characteristicDidChange events, and some changes to ScratchBLE on ready events.
* Refactoring work on PeripheralChooser and ScratchBLE.
* Some variable renaming and method signature stubs.
* Peripheral chooser method signatures.
* Moved base64 encoding/decoding to util. Some method signature formatting.
* Adding test stubs for new util and io classes.
* Adding test stub for MicroBit extension.
* Clean up for PR.
* Clean up for PR.
* Final cleanup for PR.
* Removed logging to console.
* Adding 'btoa' and 'atob' node modules and using them in Base64Util.
