EventManager: added construction and building events.
EventManager: unstable. Temp commit.
EventManager: made Buildings module keep track of buildings so that it
can do findAtTile in constant time.
Merge branch 'recent' into eventManager-unstable

Conflicts:
	library/modules/Job.cpp
EventManager: allowed plugins to specify how often they need events to be checked, in the event that monitoring is necessary.
EventManager: added syndrome event.
EventManager: fixed a few things.
EventManager: got rid of print statement.
Digging Invaders: fixed a problem with removing constructions.
DiggingInvaders: minor changes.
DiggingInvaders: fixed a problem with deconstructing hatches.
DiggingInvaders: get rid of the framework for assigning multiple dig/deconstruct/etc operations at the same time.
Digging Invaders: minor changes.
EventManager: added invasion event.
Merge branch 'eventManager' into diggingInvaders-unstable
Digging Invaders: reorganized the files to make it easier to work with.
Digging invaders: started on making invaders keep digging until done.
EventManager: Fixed a problem with deregistering event frequencies.
EventManager: made the frequency part of EventHandler.
Merge branch 'eventManager' into diggingInvaders-unstable