Merge v3.1

[nseidle]

Note: Release candidate binaries have additional debug messages turned on. Don't be alarmed if you see lots of additional serial output.

Note: If you are running firmware v3.x or greater, you can load the latest firmware or release candidate over the air. If you are using older firmware (2.x or lower) you will need to load v3.x firmware using a USB connection. We have created a Windows GUI to ease this process. Please see Updating Firmware from GUI for a step by step process.

Changes in this release:

• (Bug BLE pairing attempt from Android crashes ESP32 and reboots at handleGNSSData() #387) - Fix reboots caused by BLE NMEA streaming
• (Bug "Assisted Base" resource don't work #386) - Allow NTRIP Client to run during Survey-In for Assisted Survey-In
• (Bug Negative antenna heights not allowed #377) - Allow negative antenna heights
• (Bug File list not showing over Bluetooth config #384) - Print file list over Bluetooth from System menu
• (Feature Show HAE APC in serial menu #385) - Show HAE APC in serial menu
• (Feature Add confirm delete to File Manager and Common Coordinates list #381) - Add confirmation to file delete from AP Config page