Img class first skel
check boost in main CMakeLists.txt
unit test for img/Img.hpp
-Wall compile flag
setPixel getPixel body
iterators for Img + stupid fix on how to get pixel position (it's time to sleep)
cleanning Img.hpp (more generic, less copy n paste)
Img dimension accessors
replacing RGB_255 by GREY_255
const iterators
fixup
PGM class to dump 256 grey img
[merge] introducing Img and PGM class