Refactoring and initial test setup.

To get a proper unit test started, I've started refactoring the
functionality for the catalog into discrete modules that will be
a lot easier to test. Also messing around with using more of
Guice to make things more loosely coupled.
Moved CatalogFragment to proper package.
Removed reference to Robolectric for now.
Refactored DownloadFileTask into seperate file.
Better feedback on errors.
Better wiring of HttpClient.
Moved more code out of the Fragment class.
Added mockito
Merge branch 'master' into catalog_refactor
Fixed mockito dependency so the app runs in Eclipse again.
Better mechanism to decide between list and detail view.

There are now a number of factors in the decision, mostly based
on the presence of epub and alternate links. If an atom-link
with type alternate exists, we'll assume it to be a details-page
for the entry and load it as such. Else we'll load a fake feed
with a details-screen whenever an epub link is present.
Removed debug statement.
Removed hacky and unneeded code.
Reverted some changes.
Bit cleaner implementation.
Enabled usernames / passwords for custom sites.
Refactored edit sites dialog. Fixes #285
First steps toward better add dialogs.
Merge branch 'master' into catalog_refactor
Merge branch 'catalog_refactor'