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

Change: Shorten engine rail type drop down in autoreplace window. (#7448)

In the autoreplace window, the rail type drop down is for choosing engines
of the given time. Many rail types do not have engines specifically designed for them,
and are merely compatible with other rail types. This list is thus unwieldy and many
options have no engines available.

As this drop down is for choosing _engine_ rail type rather than compatible rail types,
we can list just the rail types explicitly listed by engines.

(svn r11802) -Fix [FS#716]: do not crash trains when leaving depot to a very long track
-Codechange: use dedicated pathfinder for signal updating, resulting in better performance and possible future improvements