The GncOptionRangeValue can be used with integers or doubles, the
default being doubles. When used for setting the plot width/height,
integers are used so all ValueTypes need to be integers other wise
the when create_range_spinner is used you end up with the upper_bound
value being G_MAXDOUBLE, a 309 character wide spin button. To
differentiate the two, use 'set_alternate(true)' for integers.