#90 Slowdown for some Firefox uses

[Chris Graham]

In manage_size, the scrollLeft and scrollTop are reset to 0 each time. However it's actually set to "0px", which is not correct. It is saved as "0". I think Firefox fails to do a comparison due to this and causes a re-render as it thinks the layout has changed.
Either that, or it just always causes a re-render even if you set to what it already is.

On computers with slow rendering, this absolutely destroys performance and makes it take about a minute to load, because it is happening every 100ms and basically locking down all other Javascript from running. I have not had this problem on my machines but multiple users have reported it and after the fix (below) it works ok.

The fix, just add some if test guards and change to not use px...

if (Á.Â.scrollTop!=0) Á.Â.scrollTop=0;
if (Á.Â.scrollLeft!=0) Á.Â.scrollLeft=0;

(That's for the minified version, I think it's this.textarea.scrollTop and this.textarea.scrollLeft on the original code)