FF3 uses negative scrollLeft positions in RTL, but FF2 does not.  This patch checks for the version of FF when get/setScrollLeft() is called.

Patch by: jlabanca, jgw
Review by: jgw (peer)



git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@5230 8db76d5a-ed1c-0410-87a9-c151d255dfc7