dead_marshes

added "safemode" to allow RfCat startup (with limitations) for borked dongles using firmware compiled with sdcc>3.5.0 (mostly so we can get into bootloader mode without tapping the magic pin headers, but also for troubleshooting)
bugfixes in vstruct and unittests
bugfixes in rfcat_bootloader (py3 works now! although slow verification :( )