DivLogger - allow disabling of autoscroll

[GoogleCodeExporter]

gwt-log 3.04 & gwt 2.04

Setting the value of the runtime log level in the DivLogger doesn't do 
anything.  Messages with finer levels of logging still appear in the window.

This relates to my other issue: you should be able to turn off the 
autoscrolling in the divlogger so that you stay looking at the portion of text 
you're viewing instead of always scrolling to the end every time there's a new 
message.  I like that it does that by default, but if I can't disable it, and I 
have a polling trace messages being displayed, and I can't hide log levels, 
then I have no way of viewing previously logged messages.

Original issue reported on code.google.com by bradley....@gmail.com on 27 Oct 2010 at 4:47