if entry has content:encoded save it as content
Merge pull request #22 from Kjwon15/rss2-content-fix

if entry has content:encoded save it as content
Feed has to be mergeable
Rename libearth.feedlist to libearth.subscribe
Docs theme
Workaround RTD's annoying hack
reduce should return a tuple
Add tests for class Stage
Document might implement __bool__/__nonzero__
Subscription list become a pure document element

It's a necessary process to synchronize the
subscription list between multiple installations.
Stage subscription list
Merge branch 'subscribe'
SubscriptionList has to be mergeable to stage
Erase the unsed function
Fix update bug of subscription set
Filtered subsets
Merge branch 'master' of https://github.com/earthreader/libearth
Fix all Sphinx build errors
Remove useless print codes
Stage subscriptions test