Change command-line parser to check for duplicate load/new game options.
Don't stop at the first one found.
Use vector instead of forward_list for gui panel lists.
Move list struct into a separate header.
Add container_unordered_remove/if to utils header.
Fix include/main/main.h putting header guard in wrong place.
Initial fixes for some of the issues with the train motion code.
Signed/unsigned arithmetic issues.
Clarify/fix unit issues.
Add some comments/parameter descriptions.
Various acceleration/braking bugs.
Fix covered track speed limit init.
Very preliminary train list window.
Uses a basic wxGrid to show a few train properties.
Add gprof and -fsanitize options to makefile.
Inline/template ReservationEnumeration functions.
This gets rid of a lot of std::function overhead, as a lot of
frequently used functions are implemented in terms of these.
Minor style improvement: use range-based for.