Code Review.
Merge pull request #126 from square/dimitris/dispatcher

Picasso 2.0
Part Deux
Hook up fetch() call, generify Request class.
Merge pull request #128 from square/dimitris/callback

Hook up fetch() call, generify Request class.
Make the imports sense
Merge pull request #129 from square/blom/make-clear

Make the imports sense
Fix tests.
Add @Config annotation to tests.
Let worker threads check cache instead of dispatcher.
Merge pull request #130 from square/dimitris/cache-hunter

Let worker threads check cache instead of dispatcher.