(svn r3217) Fix issue with resizing stepped windows introduced in revision 3181.

(svn r3216) - Fix (regression): endless loop introduced in revision 3190

(svn r3215) - Fix: warning on VS.NET 2003 complaining about constness reintroduced by revision 3192

(svn r3214) -Feature: openttd.cfg can now set how many autosaves to keep before starting to overwrite old ones
max_autosave_num in the config files sets the number of autosaves to keep (default 16)
MAX_NUM_AUTOSAVES in Makefile.config sets the default value. 16 is used if no value is given
this behaviour can still be overwritten by keep_all_autosave (openttd.config setting)
Note: this is a requested behaviour for PDA ports, since they got limited storage space

(svn r3213) - Codechange: Clean up handling of road stops, avoiding unnecessary use of pointers and using the *BIT() macros.

(svn r3212) - Waypoints/Depots: Store waypoint index in m2 for waypoints. This moves the ground type bits from m2 to m4 for waypoints and depots (leaving room for depot index in m2 in future), and moves the custom graphics ID to the waypoint struct.
- Waypoints: Until now stat_id was saved but never assigned to. Instead we now save the GRFID/local index of the custom graphics so that GRF file changes can leave graphics intact.

(svn r3211) Fix typo in r3181

(svn r3210) -Codechange: use IsRailWaypoint where possible (instead of magicnumbers)
-Codechange: IsRailWaypoint should take 'tile', not 'm5'

(svn r3209) In TileLoop_Track(), use names based on function rather than their place in the map array.

(svn r3208) Don't explicitly pass the engine type to look for to GetRearEngine(), because it's the engine type of the vehicle which gets passed as first parameter