use imsg_get_data() instead of accessing

rename ibuf arguments to imsgbuf ibuf is just too confusing since there is also the 'struct ibuf'.

remove unused control_imsg_relay

update bundled imsg

tweak amused-termux-notification - path to the socket is not necessary anymore since we respect $TMPDIR now which is set by termux - no need to hardcode the executable path, use an environment variable instead. (this is because "callback" commands from termux don't inherit the environment)

honour TMPDIR This makes using amused a bit nicer on termux where /tmp/ can't be written (or doesn't even exists.) amused still uses /tmp/ if TMPDIR is not specified.

+x amused-termux-notification

add contrib/amused-termux-notification it shows a persistent notification on android with the song file name and some buttons to control the playback. needs Termux::API from f-droid otherwise it hangs.

add android/oboe notes

add a liboboe audio backend for android Oboe is a Google C++ library for audio on Android. The backend is currently based on the libao skeleton since I couldn't get it to play audio in a non-blocking way. (It would also be pointless since there isn't a way to poll(1).) It would be worthing experimenting with the callback API. So far, it works on my phone under termux. I can control amused with amused-web. It still lacks a test in the configure since we would need to use C++ for it.

add compat for getdtablesize()

fix build when there is no system endian.h

note that libmd is needed on mac too

ooops, fix path

add missing #include for endian.h in imsg compat