Support for interior doors (with "double doors" option)

[parar020100]

This is already WIP by me

I'd like to have a setting to select the interior doors behaviour

• default (specified by interior)
• sync (open when the exterior doors open)
• openable by hand (example: 1963 with double doors)
• non-clickable, toggled by switch, opened by default (example: 1983 with double doors)

Plus, there might be options for:

• auto close after delay
• auto open when player enters
• auto open when player approaches (?)