[Ogre] Hidden movement idea

[David Morse]

> Revealed weapon systems may use active scanners instead of firing at the
> start of their fire phase.  For each attempt roll one die add the range of
> the weapon and subtract three and if the result is greater or equal to the
> range to the designated concealed counter then that counter is revealed.

How about something proportional to Range*AttackStrength, rather than
just Range, since presumably the heavy tank has better active scanners
than a GEV-PC...