[point_iterator] define points_{begin,end} as inline free functions;
[point_iterator] move flatten and concatenate iterator implementation in iterators/ directory;
[point_iterator] moved files to proper directories
[point_iterator][concatenate_iterator] fix issues in copy constructor;
[point_iterator][flatten_iterator] polish code a bit; fix problems with copy constructor;
[point_iterator] change namespace from core_dispatch to dispatch; fix macros of files due to new location;
[point_iterator] move code to new namespace; remove comments; points_begin/point_end now return point_iterator<Geometry> class (suggested by Adam);
[point_iterator] changes due to new location of files and namespaces used;
[point_iterator] adda bit more testing (dereference point iterator); now using boost::assign::tuple_list_of instead of multipoints for giving expected output;