Group include directives, sort within group:
* In headers of GIL core and extensions:
1. boost/gil/extension/*
2. boost/gil/*
3. boost/*
4. C++ standard library headers
* In programs:
1. boost/gil/*
2. boost/*
3. C++ standard library headers
4. "xxx.hpp" for local headers
Add basic guidelines to CONTRIBUTING.md.
Add/Remove #include <boost/config.hpp> or std headers un/necessary.
Rename gil_concept.hpp to concepts.hpp.
Remove gil_all.hpp - we already have all-in-one boost/gil.hpp.
Tidy up and unify copyright and license header.
Tidy up formatting and excessive whitespaces in some comments.
Remove Doxygen block with file description, author, date, etc.
Remove dead or commented pragmas and directives.
Trim trailing whitespaces.
* Applies patch from John Femiani submitted via Trac
https://svn.boost.org/trac10/ticket/2222 description:
It would be convenient if GIL views modeled ReversibleCollection concept.
In fact they almost do already. Without modeling this concept, it is
hard to use an image view with boost::range algorithms.
* Add related image_view concepts for Collection, ForwardCollection,
ReversibleCollection.
* Add tests for the new concepts.
* Add run-time tests for the new image_view methods.
* Apply patch from https://svn.boost.org/trac10/ticket/8896
* Add compile-time test of RandomAccessNDImageViewConcept
* Confirms the reported failure (tested with GCC 7.3 and clang 5.0)
* Verifies correctness of the patch
