improvements for automatic icon size code path

--this patch add two fixes concerning automatic
icon size when contents exceed the view maximum
length.
--A) when the function is called then it also
called one more time after 1sec to confirm that
the icon size found is valid. In the past that
approach was creating an endless loop that should
not be triggered any more
--B) the grow limit was made to be equal with
the shrink limit trying to be more predictive from
the user when the items will grow or shrink. In
the future we must take care of this if the items
grow or shrink endlessly

BUG:411860
FIXED-IN:0.9.3