rearranged notes/pics on plantings page
Avoid duplicate photos on plantings (or vice versa)

Strictly speaking this doesn't prevent you adding them if you really
try, but the validation for that was beyond what I could figure out (the
docs don't help, and all SO/blog posts are outdated and didn't
work).

However, if you do somehow manage to add dups, you will never see them
again thanks to the :uniq => true in the model.  That's good enough for
me.
Merge pull request #212 from Skud/photos-view-tweak

Photos view tweak