Revert some errors in 85943656 and 9630c00c

assert that pf_control is available

0x11 is the type for AAC synchronized with LOAS
0x0f is the type for AAC synchronized with ADTS

Not everybody builds VLC from the source tree
besides that the shell code was wrong : the return value of a pipe is the one of the LAST command in the pipe.

This was triggered by DBus module using access2_Control

Refactor video_filters in modules/stream_out/transcode.c by abstracting common code into 2 new functiosn transcode_video_filter_new() and transcode_video_filter_close().

- add PID to syslog and use lowercase vlc (conforming to syslog standards)
- add the command-line verbosity control -v[0-2] to html/text/syslog
    logging, such that one can disable f.i. LOG_DEBUG from being offered
    to html/text/syslog completely.
- add the priority to the syslog message

[] cause problems in zsh completion
Changing it to () is easier than fixing zsh completion generator

Don't use non-standard extensions
Run the script in zsh

Get channels information from decoder specific config
Add (commented) useless variables from ADTS header
Detect unsupported configurations and start (commented) support

plus a bit of code factorisation

Note that saving multi-key combinations will fail right now.