* Change Web Things library to use JSON thing descriptions for all Things
* Update Mozilla Web Thing examples
* Add HTTP client and server primitives
* Add HTTP client blocks library (server library will be there in the next release)
* Add BMX280 barometric pressure sensor library (thanks, José!)
* When you click a reporter block, store the output string into the clipboard so it can be pasted into a text editor
* Show the current port name in the "disconnect" command of the Connect menu
* Windows: now includes the COM port "friendly name" in the serial port menu
* Windows: now filters out Bluetooth COM ports
* Windows: remove the earlier auto-connect workaround
* Windows: now uses SDL2.0.12 for graphics