eliminate eval-viewer view - instead we can have the gfx view rule spec table optionally define tab view specs itself, and those can be separately registered from the sort of 'base' tab views. then we can map from gfx-view-rule -> dedicated-tab-view-spec

src/df/core/df_core.mdesk

@@ -462,12 +462,10 @@ DF_CoreCmdTable://               |            |                  |
 //                          rows, this stage offers the ability to build a ui
 //                          stretching over all of the rows.
 //
-// whole ui build, "wu"  -> sometimes, more sophisticated interfaces need to be
-//                          provided for a view rule, that stretch beyond the
-//                          limits of what could be offered inside a watch
-//                          window block. in such cases, the eval/view-rule
-//                          combo will be granted its own tab for example, and
-//                          this stage is used to fill such a ui.
+// tab ui build, "tu"    -> when a view rule also wants to implement ui for a
+//                          dedicated tab, it can supply hooks for that as well
+//                          in which case an eval/view-rule can be opened in a
+//                          fully fledged, dedicated ui
 //
 // A few other bits are included for various ways in which a view rule may be
 // applied throughout the eval visualization pipeline. A list follows: