Knock back limit

[GoogleCodeExporter]

Since the knock back involves a lot of factors it's difficult to know what the 
resulting knock back will be.

An example is the knife; if a human stab a zombie from behind it might fly 
across the map, but the zombie is only pushed a bit when stabbing in front. A 
limit might prevent these accidents. The knife knock back must be high enough 
so they can stab in front, but from behind it will be too much.

Make support for a optional knock back limit on various parts. There could be a 
global limit, and a limit per feature (class, weapon, hit group). If there are 
multiple limits involved (for each feature), the lowest limit is used.

Original issue reported on code.google.com by richard.helgeby@gmail.com on 27 May 2011 at 1:29

[GoogleCodeExporter]

Also add a log message if the limit is reached, so admins can tune settings. 
The log message must be optional too because sometimes it's impossible to fix 
this.

Original comment by richard.helgeby@gmail.com on 27 May 2011 at 1:32