[feature/point iterator] implementation of point iterator for most geometries (not yet for point, segment & box);
[point iterator] add missing definition of from_wkt in unit test;
[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;
[point_iterator] make private the constructor of point_iterator that takes the base class as argument;
[point_iterator] minor and stylistic changes; in concatenate_iterator use enable_if_c instead of enable_if (shorter code);
[point_iterator] remove function call that is not meaningful;
[point_iterator] minor stylistic changes;
[point_iterator][concatenate_iterator] add separate unit test;
[point_iterator] add separate unit test for flatten iterator; updated Jamfile to run the unit tests for point/concatenate/flatten iterator;
[point iterator] minor staylistic changes in unit test for concatenate iterator;
Merge pull request #4 from mkaravel/feature/point_iterator

Merge feature/point_iterator into develop
Merge branch 'develop' of https://github.com/boostorg/geometry into feature/distance