Merge branch 't/lib_arg_with'

Merge branch 't/lib_arg_with'

Was cooking in next for three weeks.

* t/lib_arg_with:
  build: Fix curses detection.
  build: Convert curses detection to new macros.
  build: Convert libreadline detection to new macros.
  build: Convert oss detection to new macros.
  build: Convert libsamplerate detection to new macros.
  build: Convert libao detection to new macros.
  build: Convert alsa detection to new macros.
  build: Convert flac detection to new macros.
  build: Convert libid3tag detection to new macros.
  build: Convert mad detection to new macros.
  build: Convert faad detection to new macros.
  build: Convert crypto detection/selection to new macros.
  build: Convert opus detection to new macros.
  build: Convert speex detection to new macros.
  build: convert vorbis detection to new macros.
  build: Convert ogg detection to new macros.
  build: Reduce redundancy in configure.ac, convert osl detection.