Includes and defining structures in PhAb

I just got 6.3 installed, and PhAb appears to have changed a bit… so
I have two questions:

  1. Where can add include paths in PhAb, I can add library link paths in
    Project->Properties…, but not include ones. I just want to do the
    equivelent of ‘-I/home/garry/myheaders’ like I can compiling without

  2. Where is the best place to define structures? If I do it in my
    main.c, proto.h will not compile, as it refers to structures it has not
    seen yet. If I define them in proto.h, they get removed everytime
    proto.h is rewritten by PhAb.

Any help much appreciated.