TTD stores invalid orders different than OTTD, this resulted in empty lines in the order list. With the overhaul of the order system this got worse: no line was shown at all.
Fix this by sanity checking while loading and convert the orders accordingly.
This adds no functionality, but is a stepping stone for future improvement (like 16bit order indices) and is easier to read.
This changes preserves binary compatibility wrt savegames.
- reduce to 2 sizes (*DParam64 for 64bit values, *DParam for the rest)
- use inline functions instead of macros
- add assert()s to check for buffer overruns
This includes 2 fixes
-Fix: [1048596] Monorail and Maglev sounds are swapped (r511)
-Add special case to load the jackhammer sound (r478)
The rest are cleanups und enumeration to make merging possible/easier
-Fix: Sorter icon pointing down 'v' sorts in every window lowest value first, '^' highest value first
-CodeChange: move Dropdownlist from settings_gui.c to widget.c. More in place there.
