[SyncEvolution] Failure to compile libsynthesis with gcc 4.6.0 on Fedora 15

Hi, I was unable to compile the latest libsynthesis git (master) with gcc 4.6.0 on Fedora 15. The problem was that offsetof() function is used in 2 places but the cstddef header is not included. Please find the patch in attachment. Kr, -- Dr. Christophe Dumez Linux Software Engineer Intel Finland Oy - Open Source Technology Center