Merge pull request #6 from bengler/master

Ruby 1.8 compatibility
Removed trailing whitespace
Make the x? methods rilly indifferent
Added rake as a dev dep
Really fixed the indifference problem with predicates
Use default signature in :respond_to?
Merge pull request #9 from kytrinyx/fix-respond-to

Fix default signature for :respond_to?
Bump version
Fix #to_json signature to be compatible with 'json' gem and Ruby's native 'json' library support, so that DeepStruct::DeepWrapper can be nested inside other hashes.