* Handle missing GUIChat element gracefully.
* Handle local player classes that have no GetTeamNumber method when
checking commander tag visibility.

The existing require usage depends on a package loader added in
TraceTracker.lua, which doesn't return error messages.

This provides the same behaviour, but with the added benefit of a clear
error message when loading fails.

In places that handle dispatching arbitrary numbers of arguments, use
code generation to provide fixed argument size variations of dispatchers
rather than taking a vararg. This avoids NYI aborts, allowing these code
paths to be compiled.

Additionally, a few other places that caused aborts have been fixed,
such as colour checking (getmetatable on cdata aborts traces) and
extension event insertion (replacing closures with callable tables).

The overall result of this is an order of magnitude performance
improvement in hook calling/broadcasting and SGUI child event
propagation, as well as other minor improvements from LuaJIT being more
free to compile code.

This maintains backwards compatibility, even if it isn't ideal
behaviour.

Use the maximum of a custom handler's argument count, and the original
function's argument count.

This provides a vote to end the current round as a draw. It only
considers votes from players that are playing in the round, and has
a lengthy delay and high vote count requirement by default.

Make the background the only element that eases.

Converts easing functions from the built-in easing library into a form
that can be used with SGUI.

* Fix labels sometimes becoming invisible.
* Fix a rare script error due to modifying the layout elements directly.
* Improve fading to fade out the background segment of an entry along
with the label.

* Add a distance tolerance to account for players that are stuck but
still jittering slightly.
* Use the player's view position as the origin to look for spawn points
from to avoid small objects at the player's feet being considered walls.

Track when the mouse enters and leaves elements, and only call the
OnMouseMove event for child elements when the mouse is inside their
parent or the mouse has just left the parent.

These changes also simplify mouse bounds checks, removing highlight
multipliers and moving custom bounds to their own method.

Automatically queue the destruction to run after the event has been
called to avoid destroying GUIItems that may be used in later parts
of the event.

* Make easing callbacks pass the SGUI control as the first argument.
This makes avoiding closures much easier.
* Allow passing data with timers to avoid needing closures for
callbacks.
* Refactor various places that create functions at runtime to use either
callable tables or pre-defined functions instead.
* Remove some tail calls that fail to compile.

This avoids using Client.GetCursorPosScreen which doens't compile.

When destroying inside an event, detach the control to avoid it showing
up in iterations.

Use it for calls to AddProperty/AddBoundProperty to pre-populate it
with most setter names.

This avoids needing a closure when creating binding sources.

This generates more optimal code that avoids loops and upvalues.

If the bar is clicked during fade-in, make sure the fade is cancelled.

If a map vote starts while the player has yet to trigger the
ClientConfirmConnect event, they would not have the datatable values
that indicate the type of vote.

Datatables will now be sent at client connection time to ensure they are
immediately in sync.

Also fire the property change event.

* Fix map selection state not being set properly when opening the menu.
* Fix error when opening the menu due to highlighting changing before
the tile is setup.

When becoming visible again, or changing parent, the mouse state should
be invalidated.

Server.GetOwner is not compiled.

Now extension hooks are added directly with Hook.Add using a unique key.
This avoids a second level of dispatching which improves performance.

There's no reason for priorities to be integers, and this allows
extension callbacks to keep their -19.5 priority.

ffi.istype returns true for ctypes as well as cdata, which breaks if
the colour or vector ctypes end up in a table that's being printed (e.g.
if they're in a stack trace).

Avoid needing to check every plugin if no plugins have hooked into a
given event or the newly enabled plugin has no method for it.