* make it possible to update tile lists of non-default terrain

* this is neccessary to get valid pointers in tiles and creatures when copying a SimState
 * add a copy-constructor to Terrain that makes a deep copy of it
 * add copy-constructor to SimState
 * add Tile-copy-constructor, it copies everything except it's Creature Lists
 * removed unnecessary comments
 * added stasis pod
 * updated stasis pod API
 * added stasis pod implementation, untested
 * fixing stasis pod
 * fixing terrain
 * fixing tile
 * fixing sim state
 * fixing creature
 * fixed massive brainfuck
 * added StasispodIOPlugin
Merge branch 'master' into newsaves
 * added StasisPodIOPlugin as friend of StasisPod
 * fixed some brainfarts
 * added tawTop and peekTop for convenience
 * freeze current SimState every 'freezeRate' ticks