Implement Feeds API #feeds method.
add feed method to get specific feed, middleware to parse feeds
Add collaborator? method to client
Merge pull request #379 from md5/check-user-collaborator

Add collaborator? method to client
Merge pull request #374 from joeyw/implement-feeds-api

Implement Feeds API #feeds method.
Modify paginate to take a block for custom concatination of the requests.
Add custom concatination block to Search#search

The search api wraps the results in a layer, this change provides a block to
the paginate method to custom combine the results.
Merge pull request #382 from joeyw/fix-search-pagination

Fix search auto pagination