This is a first round by looking at all the headers of the flake, basicflakes, odf pigment library and also lcms2engine plugin.
No cpp has been looked for improvement, i've only added the includes needed to compile.
There is also a small change to the library dependency for lcms2engine which halves the compiling time of the lib, due to linking to a lighter dependendancy.
I've put it here so we can keep track of the changes.. and to see if you find anything wrong about it.