Fix viewport-px / world-px confusion in ScreenMap. Fixes #3964.
Extract contrail fading for dead projectiles into an IEffect.
Introduce Keycode to simplify key checks.
Remove VirtKey and KeyName.
Merge pull request #3975 from pchote/contrail-fix

Extract contrail fading for dead projectiles into an IEffect.
Merge pull request #3974 from pchote/frozen-actor-fix

Fix bogus screen-map queries.
Add a Hotkey class for user-configurable keys. Fixes #3779.

Users can now define and use hotkeys that include modifiers (ctrl/meta/shift/alt).
Merge pull request #3969 from pchote/hotkeys

Improved hotkey support
Support bottom-aligned scroll panels.
Remove desyncing fp from WPos.LerpQuadratic. Fixes #3966.
Merge pull request #3984 from pchote/desync-fix

Remove desync from WPos.LerpQuadratic.
Update README.md

minor changes
Fix misnamed install image.
C&C main menu improvements:

- Disable target reticle when a window is open.
- Show the faction logos when the shellmap is disabled.
Replace cash tick options with a simple on/off.
Re-enable cash ticks in C&C.
Merge pull request #3990 from pchote/cnc-menu-improvements

C&C main menu polish.
Merge pull request #3989 from pchote/cash-ticks

Improve cash ticks.
Update mod.yaml

removed invalid tab
Clean up chat input.

- Team chat by default; use tab key or button to change.
- Removed "Use RETURN key..." prompt.
- Remove jarring transition between display and entry modes.
- Scroll to bottom on opening entry mode.
- Disable any/team toggle for spectators.
- Minor spacing/padding tweaks.
- Code cleanup.