* savegames stored an index in the switch table and performed no validation when loading a savegame.
* setting of a random switch animation duration was broken.
* separated the 2 values stored in the Time variable into 2 separate variables.
* defining a switch with one texture already belonging to another switch could leave broken definitions in the switch table.
- added function for serializing switch and door animation pointers.
- bumped min. savegame versions due to changes to DButtonThinker and removed all current savegame compatibility code.
SVN r3030 (trunk)
