Error messages from Roody will now appear as TGMsgBox forms which require the
user to click the "Dismiss" button to acknowledge the error message.  If the
user chooses the x-axis scales for an online histogram using the mouse to select
a range on the axis, that range will be used for re-displaying the histogram
when it is refreshed. However, if the user chooses "XaxisLimits" from the
context menu, that x-axis scaling will be used for all pads on that canvas, and
a range as described above will be overridden by this scaling.