Patch v 5.5.15_3

This update adds a couple of new features, these are:
[h2]A "popup message" trigger[/h2]
This works just like the player teleport/remote trigger/etc where it will "activate" when a message is sent out with the same password as the receiver.
When activated, it will make a custom text message popup for the player:

[h2]Customize the color of text label props[/h2]
You can now use color painters to change the color of text on label props:

This patch also fixes a few bugs and makes some changes since the last update, these are:
- The open/closed state of doors is now saved when re-loading a map
- Adjusted the popup menu position for particles, lights and text signs. You can also now open and edit these menus in miniature mode too.
- Fixed bug where prop lights would scale smaller in miniature mode (this is only meant to affect props in the player's hand, not placed on the ground).
- Fixed bug where the key prop could not be dropped out of your hand, and cloned copies when it shouldn't have.
- Adjusted the UI for prop modding so that it is clearer on how to customize the control options (like being able to click to toggle a light source). Added additional help info too.
- Fixed bug where the transform edit UI would not show up when editing a button on a prop mod for the first time only.