Sort terminal strips into the plan's own order

The strip sorted by label: X1:1, X1:2 ... with X1:N and X1:PE at the
end whatever the plan looks like, so a strip drawn across pages came
out in an order no cable follows. Sort it the way the plan is drawn
instead -- folio by folio, then left to right -- in both places that
order a strip: the auto import's own sort of the terminals it groups,
and SortTerminalStripCommand, which the import pushes for a strip it
just creates and which the editor's sort button and
qet.sortTerminalStrip() push as well. The two share one comparator
(SortTerminalStripCommand::planOrderLessThan), so they cannot fight
each other. A spare stands on no folio, has no place in the plan order
and goes last, by label; the label breaks the remaining ties, so two
terminals at the very same spot keep a stable order.

sources/scripting/qetscriptapi.cpp

@@ -3314,8 +3314,9 @@ bool QetScriptApi::bridgeTerminals(int stripIndex, const QVariantList &realTermi
 
 /**
 	@brief QetScriptApi::sortTerminalStrip
-	Reorder a strip's physical positions into the canonical order the
-	editor's own "sort" button computes, through SortTerminalStripCommand.
+	Reorder a strip's physical positions into the order the plan is
+	drawn in -- folio by folio, then left to right -- the same
+	SortTerminalStripCommand the editor's own "sort" button pushes.
 */
 bool QetScriptApi::sortTerminalStrip(int stripIndex)
 {