CoeCwd9: Set multiple Curve properties functional
Bug Number: n/a
Release notes (y/n): no
For Release Nums: 7.1

See screenshot:
 http://cadswes2.colorado.edu/~philw/2017/CoeSwd9/2017-02-24/dlg1.png

"Curves" mode is essentially complete.  Multiple selected curves can be
set, with settings grouped in three optional (effect/no effect) sections:

   (1) Line Style
     - pattern (solid, dashed, dotted, etc).
     - line width (integer)
     - line color

   (2) Symbol Style
     - style (none, ellipse, rectangle, diamond, etc).
     - symbol size (integer)
     - symbol color

   (3) Curve Style
     - linear interp, spline interp, points, step curve.

Two "apply" buttons: "Apply to All" (with confirmation dialog) and 
"Apply to Selected" (one or more selected Curve items in the list).

Context menu operations on the Curve items:
   (1) Edit Label (initiates an incell-edit).
   (2) Copy Settings to Edit Controls

When the dialog is initially shown, the setting controls are initialized
from the first slot curve in the plot page.

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