vehicles: MCV enabled; msam use patriot; shroud

MCV re-enabled. A construction yard build radius will be included in a later release to rein in basewalking.
Mobile SAM launcher's weapon is Patriot missile instead of HonestJohn.
Shroud reveal ranges on a few units adjusted
Merge pull request #2776 from psydev/patch-8

vehicles: MCV enabled; msam use patriot; shroud