CoeSwd9: Replace individual slots, using GUS slot selector
Bug Number: n/a
Release notes (y/n): no
For Release Nums: 7.1

A basic level of slot replacement in Slot Curves has been implemented in 
the new "Configure Multiple Pots and Curves" dialog.  This operation is 
available in the "X axis" and "Y axis" columns, as a context menu operation
in cells which show a slot reference.  This is implemented for the following 
slot curve types:  Series, Periodic, Scalar (both time and value dimensions), 
Periodic, Parametric (two series slots), and Table. (Table Contour is 
excluded -- as is true for the existing Slot Curve dialog).

To limit the exposure to potential subtle bugs (the related slot/axis 
assignment algorithm is quite complicated) -- and to reduce the testing 
overhead -- for all but the Table Slot Curve type, the picked slot must be 
of the SAME UNIT TYPE as the original slot.  When GUS is shown, the correct 
unit type "filter" is activated.  Changing that unit type filter and picking 
a slot having a different unit type is reported to the user as an error.

Table Slot Curve slot-replacement was tested with unit changes (e.g. 
Elevation Volume Table changed to Elevation Area Table), and is working 
correctly.

Aside from the new unit-type constraint, the current state of the new 
implementation lacks the following features supported in the old Curve 
Configuration dialog:

  (1) The new feature does not support changing the Table Slot COLUMNS 
      associated with the X and Y dimensions.  The original column index 
      associations are retained.

  (2) AggSeriesSlot column selection is not supported. (Only the first 
      column can be selected).

  (3) TableSeriesSlot column selection is not supported.

See screenshots:
http://cadswes2.colorado.edu/~philw/2017/CoeSwd9/2017-03-02/Replace_SeriesSlot.png
http://cadswes2.colorado.edu/~philw/2017/CoeSwd9/2017-03-02/Replace_ScalarSlot.png
http://cadswes2.colorado.edu/~philw/2017/CoeSwd9/2017-03-02/Replace_TableSlot.png

ALSO: correction to slot icon bug for DateTime scalar slot curves.  
(The slot type icon was appearing in the wrong column).