Log Message:
Update libgee to 0.16.1

It seems that after the ABI break in 0.7, which probably should have
incurred a major version increment, libgee since 0.8 has been
backwardly compatible.

Highlights from the release notes since 0.8.8, devel/libgee0.8:

 * Workaround GC thread consuming 100% of CPU
 * Fix HashMap destructor name
 * Add explicit tee implementations
 * Add UnrolledLinkedList class implementing List and Deque interface
 * Clarify the add and insert operation on list iterators and make the behaviour \ 
consistent for ArrayList and LinkedList
 * Allow (partially) disable internal asserts
 * Internal symbols are hidden
 * Fix HazardPointer bugs
 * Fix List test
 * Remove workaround for 'old' (<0.23.2) vala
 * Use WeakRef for keeping of read-only proxy for collection
 * The collection cloning no longer leaks memory
 * Override read_only_view property in ReadOnlySortedMap and its subclasses
 * Add adding to collection based on iterators
 * Make Collection.add_all_array, contains_all_array and remove_all_array virtual
 * Avoid destroy coroutine creation in hazard pointer implementation
 * Add Traversable.tee
 * Add exception handling to Future
 * Add ability of getting Future from Lazy
 * Make Traversable.flat_map a virtual function
 * Add more specializations to .foreach
 * Add flat_map method to Traversable
 * Add zip method to Future
 * Specialize stream iterator (4-22% speed improvement in tests)
 * Extend the Traversable.Stream with Stream.WAIT
 * Fix lazy value usage in unfold
 * Add futures and promises to libgee
 * Return true from HashSet.Iterator.foreach() if we fall off the end
 * Fix memory leak in TreeSet and TreeMap
 * ConcurrentSet implements SortedSet
 * Fix HashMultiMap, TreeMultiSet constructor
 * Add add/contains/remove_all working on array
 * Allow creation of ArrayList from array
 * Add read_only_view to Gee.MultiSet and Gee.MultiMap
 * ConcurrentSet preliminary implementation
 * Allow slice in ReadOnlyList
 * Fix Iterator.remove in PriorityQueue
 * Add foreach specializations
 * Use foreach function instead of iterators

For full details see:
https://git.gnome.org/browse/libgee/tree/NEWS?h=0.16.1