Navbar

Rearranged the navbar with "Your Stuff" as discussed on the mailing list.

In order for the links to actually work, I had to make the plantings, gardens, and posts pages work like the seed page in having an "owner" option, so you could see just one person's stuff, or everyone's stuff.

I also rearranged the routing so that it's /seeds/owner/skud rather than /seeds/owner_id=1