add beacon app, some Kconfig improvements. Repeated transmission reveals a transmission problem where the FIFO is filled but transmission does not start.

updater: blank check before erasing fw partition. Also fix nasty bug in bootloader spiflash waitwritecomplete().

Tools: detect that update app has started

add MTD ops in mtdchar ioctls
remove control of internal leds in the bootloader
flash external red during bootloader execution, start external orange to signal download mode.

turn useless status app into updater. add skeletons for firmware update tool and host pc update sender

Move all build defconfigs to their own folder
Update main readme according to new folder structure