CHIRP

[developer] Control address format for full-file dump/diff

A full-file hex dump/diff display is invoked by selecting View --> Developer
--> Diff tabs, and then in the "Diff Radios" popup, selecting < 0 for
either or both memory locations. The address printed for each line of
this display is in decimal.

Since the source code associated with manipulating the memory structures
usually uses offsets specified in hex, this involves off-line base
conversion by the developer. On the other hand, some users may find
the existing decimal format more useful.

This change adds a [developer] section directive "hexdump_addrfmt"
which takes values of "decimal", "hex", or "both", allowing developers
to see the address as they prefer. The default remains "decimal".
If the value supplied is not recognized, a log message is printed
and the default is used.

The decimal format, where printed, now prints a minimum of 4 digits
instead of 3, to eliminate the column alignment break at address 1000.

README.developers is modified to document hexdump_addrfmt, and also
to put the directive descriptions in alphabetical order, and other
small corrections.