* Use target_include_directories to specify include paths
* Specify project root (parent of rtgui and rtengine) as include path
* Replace relative includes with normal includes
modifying the global ProcEvent enum and refreshmap array is not needed
anymore. You can now register new events dynamically, using a ProcEventMapper
instance. See rtgui/localcontrast.cc for an example.
Hopefully this solves the problem of recurring merge conflicts when different
devs add different proc events
