Patch limit_rate_max: for your review

[crirus]

Hello

I have a new patch for Nginx. I use this server to stream videos. I needed a
way to burst the rate with limit_rate_after but controlled from config, not
at full throttle. Eg.: send 4Mb with 500KBps and the remaining with 90KBps.

This is usefull when sending mp4 that have a 2 to 6MB of index data at the
beginning of the file and playback only starts after this is received. This
way I can start the video playback faster not after 20 seconds or so.
However, if you have 500 new users per seconds you can choke the bandwidth
so the need to control the burst speed.

I created a new config directive limit_rate_max that applies to initial
burst speed.
Another change I made is to put the limit_rate_after in server variables.
I need this to control the burst quantity on the fly based on url param.

    if ($arg_burst != ""){
        $limit_rate_after $arg_burst;
    }

The index for each file is different and with this I control how much burst
we need, usefull when users seek a lot and index is recalculated on seek for
each file...

If anyone can review this and find it useful, let me know, it works for my
needs.

I thank to Andrei (Latzease) for his contribution to this... he made it
happen.

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,232178,232178#msg-232178