Config writer needs flash ID verification

[cr]

The config writer currently happily rewrites the flash ID at offset 0x100 with a mismatching value, but it should warn the user if they try and ask if they are --really sure.

[johannessen]

At first glance, I misread this and thought you would like a warning before overwriting the MMSI – something that has been discussed on the HX870 mailing list as a possible enhancement of the YCE15 software. My bad.

But is overwriting the data at 0x100 really an issue? ~I've been doing it the entire time since I started using pyhx870 and there was never a problem. The device seems to simply ignore that. It gives back the updated data on 0x100 next time you read it.~

~BTW, I highly doubt this is a flash ID. The values are changing every time I dump the device's memory. They appear to be some sort of time stamp, plus other data that I haven't figured out.~

[johannessen]

Oh, actually the time stamp thing is at 0x110. I apologise – I really shouldn’t have commented without checking the memory layout table first.

Please disregard my earlier comment!

[cr]

By the way, that location at 0x110 contains the date (YYMMDD), time (HHMM), and GPS coordinates (internal coordinate format) where the radio was last turned off.