[Feature] Add custom date string formats to OSD

[8none1]

I would like to be able to specify a custom strftime formatting string so that I can change the way the time is shown when overlaid on the stream.

In my case I want to add the timezone.

I was able to do this by editing the /etc/prudynt.cfg file like so:

stream0 : 
{
  osd : 
  {
    time_format: "%F %T %Z"
  };
  fps = 20;
  audio_enabled = false;
};

(The default is %F %T and so is not set in the config file)

Which results in:

I'd love to be able to specify this via the WUI as well:

[nicolasroche898]

I use time_format = "%F %T %z %a"; shows the day of the week ("Sunday") and the current numerical time offset, which can change between DST and not DST depending on season