vfs_fruit: Add capability to advertise FULLSYNC

[github at samba.org]

New comment by iliv on Samba Github repository

https://github.com/samba-team/samba/pull/64#issuecomment-355751862
Comment:
@Henrik41 somewhere in the middle of this discussion @enke5 mentioned that he was trying to include this patch in official Ubuntu samba package for version 4.3. I am wondering too if they succeeded, or not. @enke5 can you, please, tell us how things are looking for 4.3 on Ubuntu 16? I personally would love to see this patch in 4.3 and not having to wait for 4.8, which won't be shipped as part of LTS anyway I guess.