initial commit
removed cpp/tutorial_code/images/
fixed warnings in documents
fixed display_image tutorial sample
Update tutorials.rst

Change some wording
Update table_of_content_introduction.rst
ability to compile for iOS with Neon
yet another attempt to refactor features2d; the first commit, features2d does not even compile
improved cloning test
improve decolor tests
fix regressiont ests npr
fix grayscale loading
constness
adds header guards + move impl to proper file
rename stuff, adds logging and replace shitty else if chain by switch
refactor array_product
rename variables
remove useless buffers
backport bug fix
remove some more useless buffers and rename a bunch of variables