Change: Decouple and remove landscape-dependent cargo types. (#11719)

Cargo types of default engines, industries and houses are now specified in terms of label.

Codechange: Split CT_INVALID into CT_INVALID and INVALID_CARGO.

INVALID_CARGO is a CargoID and should be used for most purposes in game.
CT_INVALID is a CargoType used for defining default properties.

Fix: Calculation of initial engine age was inaccurate. (#11660)

Engine age in months was calculated as the difference in days / 32, instead of the actually difference in months. This would result in engines being artificially younger if a game was started at a later date.

Codechange: Replace reliability magic numbers with constants.

These are derived as a percentage of UINT16_MAX.

Codechange: Add base() method to StrongType to allow access to the base type without casting. (#11445)

This removes the ability to explicitly cast to the base type, but the requirement
to use .base() means the conversion is still explicit.

Fix: Check for engine variant loops during NewGRF initialization. (#11343)

Invalid NewGRFs could set up an engine variant loop that never ends. This
was checked for in some places that evaluated variants, but not all. In
most cases this would result in the engines not appearing, but could
potentially cause an infinite loop and crash.

Instead, during NewGRF initialization detect loops and remove invalid
variants before setting display flags.

Codechange: automatic adding of _t to (u)int types, and WChar to char32_t

for i in `find src -type f|grep -v 3rdparty/fmt|grep -v 3rdparty/catch2|grep -v 3rdparty/opengl|grep -v stdafx.h`; do sed 's/uint16& /uint16 \&/g;s/int8\([ >*),;[]\)/int8_t\1/g;s/int16\([ >*),;[]\)/int16_t\1/g;s/int32\([ >*),;[]\)/int32_t\1/g;s/int64\([ >*),;[]\)/int64_t\1/g;s/ uint32(/ uint32_t(/g;s/_uint8_t/_uint8/;s/Uint8_t/Uint8/;s/ft_int64_t/ft_int64/g;s/uint64$/uint64_t/;s/WChar/char32_t/g;s/char32_t char32_t/char32_t WChar/' -i $i; done

Codechange: Use IsValidCargoID/IsValidCargoType.

IsValidCargoType() is used only for unmapped IDs.

Change: Units-system can convert from N to kN, don't preconvert.

This allows force to passed as is and avoid premature rounding.

The AI function "GetMaxTractiveEffort" still needs to return kN to avoid breaking the API.

Change: Add extra random seed to StartupEngines().

This means that calling reset_engines will rerandomise introduction dates
and reliability.

Probably not necessary.

Change: Mark build/autoreplace windows dirty less often in monthy loop.

These window classes were marked dirty for every engine that had
reliability calculated every month.

Fix: [NewGRF] Default value of RailVehicleInfo::railveh_type was inconsistent with other default properties. (#9967)

If a NewGRF assigned neither "power" nor "dual-headed" properties,
then "railveh_type" defaulted to "singlehead-engine", while "power=0" said "it's a wagon".

Codechange: Let the compile generate the master command table out of templated command traits.

This is using a non-intrusive type-traits like templated system, which
allows compile-time validation that the command table and the command
enum match up.

Codechange: use "[[maybe_unused]]" instead of a wide variety of other ways we had

While at it, replace OTTD_ASSERT with WITH_ASSERT, as this
is always set if assert() is valid. No matter if NDEBUG is set
or not.

Codechange: Use C++ features for train wagon overrides. (#9141)

This removes the need for C-style array management and allows use of iterators to perform wagon override lookups.

Fix 85a49a0d: invalidate airport toolbar when new planes become available (#8532)

Otherwise if the airport button is disabled, it will remain disabled
until you close/open the toolbar again.

Feature: GS method to control engine availability for a specific company (#7791)

* Feature: GS method to allow company to use an engine before its introduction date

* Feature: GS method to retire an engine early for a specific company