Show, Eq, Ord: handle `_`.
Fix whitespace violations.
Set default loc to typ.ptyp_loc in [%derive...] (fixes #13).
add an example of deep tree, to show how it prints, in src_examples/print_test
slightly different printing of variants
fix tests
Merge pull request #15 from c-cube/update_show

slightly different printing of variants
Add version to opam file (fixes #10).
Don't invoke opam query for targets other than release.
Update README to improve plugin testing instructions.
ppx_deriving_random + its tests