Boring changes \o/

https://github.com/dbr/OpenColorIO/commit/f103709ec085bdaa03a3ea446d5b928d8327ffbc
Add Boost 1.44 and 1.45 to additional versions list (1.45 works fine, can't
imagine 1.44 is incompatible)
Move the find OpenGL/OIIO stuff into OCIOMacros. Probably belongs in a
Find___.cmake file
Try and find OIIO/OpenGL/etc, build applications if they are found
Components more consistently check if their requirements are met in the root
CMakeLists.txt, rather than wrapping the components CMakeList in an if()
statement. This makes it easy to see what components have requirements by
looking at one file
Tidier and hopefully more helpful messages regarding applications and their
requirements