Added trigger types that cause the level to end in victory or defeat.
Exposed method in Triggerable that unsubscribes from all switches.
Win and lose conditions are now read from level files and stored in the LevelManager
Added shell of a method to handle ON_END_CONDITIONS_MET messages. Alex will know what to do.
Added sample GoalZones to Playtest2_03
Addressed comments on pull request
Since win conditions are now required, a <links> tag is now also required for levels.
Added a rudimentary win condition to SD_TestScene to make it playable under new requirements
Merge pull request #91 from VajraFramework/victory_and_defeat

Victory and defeat