Ref #38. Implemented remove and added into demo app. Added convenience method to instantiate internal maps in response to a bug fix whereby filtering map didn't create the correct type of map. Child2Group cache is now a WeakReferencedMap. Should help reduce leaking due to a child key no longer having the same hashcode. Would happen if object was changed outside of adapter. Fixed bug where areGroupsSorted would get overriden but not reflect the change. Minor documentation adjustments.
Minor documentation adjustments