EdgeScroll and pixel steps

[Viktor Griph]

Currently EdgeScroll divides pixel steps>1000 by 1000 and enables wrap. I 
belive this to be a bug (and is reportd as sush (#3162)). However, it is 
useful to allow for warps when using pixel steps as well, so just removing 
that ability is no good solution.

One possible solution would be to add another way of specifying wraps to 
the syntax, and make it the required method for pixel sizes (or change 
the check with pixels so that the size has to be larger than the screen 
width, and an even multiplicand of 1000, in order for division to take 
place (for compability with configs using for example EdgeScroll 1024000p 
768000p)).

I can think of several possible syntaxes, and can't decide on which one is 
best. One can either add a prefix (or another suffix) option 'w' to the 
individual coordinates. (w1024p or (1024pw or 1024wp)), or one can add 
optional keywords to the EdgeScroll syntax after the step parameters. 
(i.e. EdgeScroll 1024p 768p wrap|wrapx|wrapy)

/Viktor