AutoExplore go to "special" terrain (like glowing chests) once like it does...

AutoExplore go to "special" terrain (like glowing chests) once like it does items. Tries to ignore them afterwards, but will still stop at them if "block_move" tests to true.
AutoExplore only go to vault doors once
AutoExplore don't stop exploring because of losing air until less than 75% max air capacity.
AutoExplore don't repeatedly stop at escort portals
AutoExplore specify the direction of seen hostile


git-svn-id: http://svn.net-core.org/repos/t-engine4@6104 51575b47-30f0-44d4-a5cc-537603b46e54