Basic parsing and storage of Hexen MAPINFO data.
* Propagation of info from MAPINFO to global LevelInfo structure
* Support for global FOGMAP lump in colormap lookup functions, for Hexen's benefit
* Some refactoring of intermission level name handling (more work needed)
* Support for separate finale data for secret exits versus normal exits
* finale-early flag controls whether finale happens before an intermission
Rewrote Hexen MAPINFO parser to store data in metatables.
* New experimental EMAPINFO parser (has not replaced the one used in p_info yet as needs more testing).
* Changes to XLParser/XLTokenizer core for EMAPINFO parsing support