UI BUG:All available orders not depicted

[dsteckel]

All orders available to units should be depicted in the UI--at least, all orders not related to automation.

Repro:
o Select a military/settler/worker unit.
o Examine available order buttons for unit.
o Press "E" key ("Explore" shortcut)

Result:
Unit begins exploring.

Expect:
No action.
-or-
"Explore" button to appear in UI.