Save state of White Crystal

After the user has placed the White Crystal in Hawkthorne Entrance, keep
the door open permanently. This make it more convenient navigating
through the level because the door acts like a normal door once it the
crystal unlocks it.

This is implemented by adding a property to hiddendoortrigger called
"saveable" that when set to true, sets the variable
"doortriggers.sprite" to true, indicating that the crystal has been
used.

The saveable property could be used in other levels to make doors have
"permanence" although I have only tested it on
caste-hawkthorne-entrance. This functionality makes less since in
valley-chili-fields-2 however because the door is truly "hidden".
delete NAMESPACE variable per DaNiwa's request
Updated saving to all hiddendoortriggers

Now there is no option for "saveable" door triggers as in Niamu's
suggestions. This means that all doors that are opened or shown with
hidden door triggers should now include a property called "trigger"
which indicates the trigger that it is used by. This is needed to
make doors open as soon as the level is rendered.

Affected triggers include:
* Dean's Office 2 (dalmatian)
* House (painting)
* Chili Fields (skull)
* Castle Hawkthorne Entrance (pedestal)

New hidden door triggers should now have that property or else the
loading from save feature won't load properly (the door will need to be
"fixed again").
Prevent triggers from being activated twice

This prevents the trigger from being activated again by the user once its
door has been opened. This prevents annoying messages from constantly
pestering the user.
Merge pull request #2120 from matthewbauer/savepedestal

Save state of White Crystal