Compatible with old bootloader. Adds an additional section with a copy
of the interrupt vector table to the end of the image. This is needed by
the new bootloader and should be ok for the old bootloader.
Note that for this to work, everybody needs python installed with
the IntelHex python package. On Linux this can be achieved with
pip install IntelHex
Introduce new testing-app example.
Add a new coap error code for blockwise transfer.
Add include-file for bootloader callbacks (jumptable).
Note that only the bootloader for osd-merkur-256 will support
OTA-update, the -128 simply has not enough flash memory, so only
in the -256 we have the bootloader functions in the jump-table
of the bootloader and in the bootloader-if.h include-file.
