Renamed RegionIndex.queryOverlapping() -> queryIntersects() and added an implementation under AbstractRegionIndex using IndexableShape.intersectsEdges().
Fixed potential resource leak in LegacyMySqlStoreFactory.getSql().
Removed old broken unit tests.

We may look at them in the future once those tests are needed again.
Added org.mockito:mockito-all v1.9.5 as test dependency.
Added a simple test for com.sk89q.worldguard.region.Region. Flags are not yet tested.
Replaced flags with attributes.
Added equals(), hashCode(), and toString() to Attribute.
Added support for attributes to Region.
RegionTest cleanup.
Added AttributeTest.
Made Attribute abstract, rewrote Javadocs.
Added some misisng methods to DataValuedAttribute and added a test.
Minor cleanup.
Removed parents from regions.

After a minor discussion, parent-child relationships are being removed because they:
(1) confuse users
(2) make everything much more difficult to program
(3) do not allow for a use case that is not already doable with priorities
Made the class Javadoc of AbstractRegionQueryCache sane.
Gutted ApplicableRegionSet.
Might as well make ApplicableRegionSet implement Collection<Region>.
Made ApplicationRegionSet implement Collection<Region>, and made it keep the given list sorted.
Added Stereotypes for group support for flags/attributes.

They are not yet functional because they require some extra mechanics not yet written (access to factories and whatnot).
Cleanup Attribute Javadocs.