Add basic hold-fire stance, and use it for some test maps.
Add JSON data container to map XML files, to simplify the interaction
between scripts and maps.
Fix fixed-point printing so it roundtrips safely through map files.
Fix camera startup positions in old-format maps.
This was SVN commit r7844.
Giant merge from
http://svn.wildfiregames.com/hg-source/file/5fb522019d5e
Infrastructure is largely complete, gameplay is largely missing
Disabled by default; use command-line flag "-sim2"
(Second attempt at commit...)
This was SVN commit r7259.