1. (bugfix) Workaround for a crash in toUTCString() if fix.time has the value "undefined", see https://github.com/espruino/BangleApps/issues/1155
2. (improvement) The 4-dot progress indicator is replaced by the number of satellites in view.
Tested on Bangle.js 2 with firmware 2v11
New Bangle.js firmwares remove 8 char name restriction so we're ditching the first char -> file type and using normal file extensions
Took the opportunity to remove code for older Bangle.js (since the new stuff won't work anyway)
Also removed the need for an 'app.json' - it's now renamed 'app.info' on the watch, and we just auto-generate it
Renamed a few apps so widgets all start with 'wid'