Rearranged routes so that devise worked with "members"
renamed Member.username to login_name
renamed Post.member_id to Post.author
Changed garden.member_id to garden.owner_id
Renamed default garden in /spec/factory/garden

"My Garden" was too generic and hard to test for -- tests like
rendered.should contain "Garden" are far too easy to have a false
positive pass.  So I renamed it "Springfield Community Garden" so that
false-positive passes were less likely.
Fixed up tests for garden display

These were just wrong wrongety wrong. I think they were from before we
were auto-creating a garden for new members.  Fixed now.