add documentation for glow function
fix list
fix error with equation
fix list
add default value for sigma
Images to the sepia documentation were appended.
Merge pull request #44 from valentina-kustikova/sepia_docs_fix

Add images to Sepia documentation
Merge pull request #36 from stragger/glow_documentation

Add documentation for Glow function
Clean repo
change algorithm description in Tint filter docs. rename images.
Add 2 new files and modify photoeffects.hpp
changed vignette_test.cpp
modified 3 files
Vignette implementation
modified vignette implementation
Added warmify implementation and 2 files of rst-documentation
Changed photoeffects.hpp and vignette.cpp
deleted 3 files
Modified vignette.cpp and added vignette_sample.cpp
a few changes of vignette_sample.cpp