Initial setup of the trigger files
Added vi swp files to gitignore
Moving triggers to metamodel
Triggers make more sense in structures.  Moving them again.
You can now add triggers to layers but they still do nothing.
Added docs to Trigger
Added TriggerController.
Merge branch 'master' into triggers
 * Extend trigger support.
 * Change spaces to tabs in map.cpp.
 * Added InstanceDeleteListener to TriggerChangeListener and added the related trigger condition (INSTANCE_TRIGGER_DELETE).
 * Fixed a really bad bug in instance.cpp. Activity should not be deleted in case change listeners were added.
 * Added simple trigger test to fife_tests.
 * Added saving and loading for triggers.
Merge pull request #809 from fifengine/triggers

Triggers