new master version

Merging all recent devel updates into master:

    Fix stupid bug that caused RS92 to not work with last devel version
    python3 compatibility
    Experimental: Modified DFM handling (DFM17 vs DFM09P for 0xC), untested
    Add support for RS41 short measurement frame 0x7F (#353)
    fix #342: remove bug in code for right-justified text on OLED display
    fix GD5 (untested)
    handle display off timeouts > 127 seconds correctly
    gps from apk: 0/0 as invalid pos
    set dhcp dns name to mdns name; preparation of configurable map link (dl2mf merge)
    sync w/ DL2MF: web interface enhancements
    fatal bug--