Change: Store station blocked/wires/pylons flags in map. (#11337)

This stores three flags in unused map bits, and avoids having to look up
station graphics and custom station specs to determine blocked/wires/pylons
status.

This potentially affects rail pathfinding performance.

Savegame version is not bumped, as the flags can just be updated every
time.

Fix #7307: Add WaterClass to MP_TREES, set when trees are on coast tiles (#7309)

This allows allows NewGRF object/industry placement rules to treat trees on coast tiles the same as regular bare coast.

(svn r15601) -Fix [FS#2615]: bridges/tunnels don't store tram owner making it possible to remove someone's tram tracks.
-Feature: allow building road stops on road/tram tracks of competitors.

(svn r12042) -Fix [FS#1676]: Reimplement how rivers and canals are stored in the map, allowing the sea/river/canal status to also be
stored for buoys, docks, locks and depots. All these are now allowed on rivers and removal of them will revert to the
original water type.

(svn r9315) -Merge: The newhouses branch. With this merge comes almost complete support for
the newhouses grf specs, so all newhouses grfs will be playable in the game.

Many thanks to everyone who contributed code and ideas, and all the testers
who found things we missed.

(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

(svn r5326) Remove the indicator bit for custom waypoint graphics, because it just contains redundant information
Yup-yup-ed by: peter1138

(svn r3472) - [PBS] Remove from trunk. Anyone interested can still find it in branch/pbs. This reverts revisions r3158, r3140, r3075, r2977, r2674, r2625, r2621, r2529, r2528, r2525, r2524, r2519, r2517, r2516, r2507, r2499. (in conjunction with Tron)
- The only change is that the nsignalsw.grf file is kept and that existing nightlies with PBS signals get those signals converted to combo-signals.

(svn r3445) - Fix: [ 1415379 ] Enhance documentation of lift destination
- Fix: wrong documentation of trees (Tron)

(svn r2529) - Fix: PBS signals showed up as normal signals with the query tool
- Update landscape_grid.html to show busy bits used by PBS.