The guest tracking icon is hidden on the guest list if it's in
PAGE_SUMMARISED mode. Closing then reopening the window reset it back to
INDIVIDUAL mode but did not restore the icon state.

Close #6639: Integrate Discord Rich Presence

OpenGLDrawingEngine::ConfigureCanvas calls std::ceil which is defined by
the cmath include. Adding the include directive resolves a compilation
failure to due std::ceil being otherwise undefined.

To eventually replace passing around month ticks and date.c

Shaking while at the edge of the map has been completely eliminated. In
order to do this, comparison with tile height was also removed which
fixed a few outlier cases.

The main cause was viewport axis were only being set if it's respective
isometric axis was at the boundary, instead of either isometric axis.
Viewport no longer gets stuck which was related to the shaking in the
end. (#2875)

Refactored viewport_update_position. I moved
viewport_set_underground_flag above the bounds checking function since
it had no relation to it. (#996, #2589)

Scrolling on the map edge with arrow keys or mouse edge will now go the
same speed in both directions. (#2254)

Added changelog entry.

When a maze does not have a completely hollowed out hedge the game command would return 0x8000000 as it tries to remove an element that has already been deleted. As game actions no longer use 0x80000000 to indicate a failure this would get interpreted as the refund price and cause the issue.

Fix was to introduce checks when adding up the refund price. This was done rather than changing the game action so that it can be properly fixed when get_refund_price is converted into a game action