OpenFlipper-Free

Someone apparently had the misconception that clearing a vector
deallocates the reserved memory of that vector and went through great
lengths, writing hideous code in order to avoid ever decreasing the size
of the three vectors sortedObjects_, overlayObjects_, and lineGL42Objects_.
As a result, unnecessary variables were used for unsafe and hard to
maintain bookkeeping and the size of these vectors was clumsily computed
with an O(N) linear search instead of a constant time size lookup.