Updates to eeprom support for URIs

[coolacid]

uridiag's "initialise eeprom" will kill a URIxB for sure. Also, it looks like simpleusb will store the * data in the Product String section, which is used by default on the URIxB. This is bad, but should not brick devices.

I recommend we move the data to start at 50. This is 14 bytes (7 short) from the end of what the URIxB (CM119B) uses for its internal settings. Really, we should never read/write bellow address 50.. except for reading the serial number at 03 and use that for radio detection. (I'll open an issue for this too)

We also should change the init of uridiag to only "init" addresses 50-63 so we don't kill internal settings of the CM119 (or overwrite other devices eeprom settings) (Will need to open an issue, or make sure we do both changes at the same time)

Good news is however, I have the ability to recover any URIxB devices without sending them somewhere.

We should also use a new magic number, and if the old magic number is detected, move the data to the new location.

Finally, the chips take a little longer to talk to the flash - so uridiag/* will need to add a few usleeps in places to make it work better.