(bug 25592) LogEventsList:showLogExtract should ignore WebRequest

(bug 25592) LogEventsList:showLogExtract should ignore WebRequest

LogEventsList:showLogExtract currently pays attention to WebRequest
parameters such as offset, dir, order, and limit (although limit is
typically overridden by callers, and offset sometimes too).

While these make sense for a pager that is driving the whole page, it
doesn't make much sense for the "most recent log entry" boxes that are
displayed using LogEventsList:showLogExtract. So let's have
LogEventsList:showLogExtract ignore these, and for good measure add in a
parameter to use the old behavior in case any caller really needs that.

Change-Id: Id4380cd863ba69fc9b9afb5a0034d82ad4d9cc34