incremental neighbor search classes were storing a nested ref_counted iterator
for begin() which implies that a call to operator++ on a copy of an iterator
increment the internal copy of the class (cannot make several pass).
There is still a problem in case of copy outside of the class but this is
a first step (a deep_copy method should be provided for iterators which would
need a small feature).
remove all mutable member variable and leave only one const_cast in the kd-kdtree private function
const_build. This function is called in const predicates when the tree is not already internally built.
The documentation has been update and a few typos fixed at the same time.
handle case when kdtree is empty for all 4 nearest neighbor search method
correct sort method of bounded_priority_queue (was sorting the complete vector even if not full)
==> fix the crash when k > nb input points
Modify test suite to handle these particular cases
Laurent Rineau
Sébastien Loriot
Andreas Fabri
Sylvain Pion
Laurent Saboret