(svn r8841) -Fix

Remove {,u}intswap() and replace them by Swap()

(svn r8128) -Codechange: Split sprite and palette remap into separate 32 bit values.
This lets us increase the sprite width from 14 to up to 29 bits,
effectively nulling the old sprite limit. Table changes in next commit.

(svn r8050) -Codechange: Rename map member extra to m6, since its usage has been widden.
Only doc landscape_grid.html has been updated, landscape.html will be done latter.
-CodeChange: Replace a direct access to m6 with SetTropicZone in InitializeLandscape, as it is the only part of m6 still untouched without the brute-forced m6=0