(#3118) - Typo correction

Changed 'formally' to 'formerly' to indicate 'previously' or 'in the past'
(#3122) - img partial and retro applicaton
(#3120) - small edits to guide
(#3111) - change db.compact()'s return value back
(#3124) - Compress Images
(#3126) - npm run dev works without dist/
(#3131) - add travis badge
(#2355) - Add info alert with full working example
(#3113) - Make leveldown an optional dependency
Merge remote-tracking branch 'upstream/master' into pull-replication-test
Refactored test framework to make it cleaner
(#3139) - less verbose travis logs
(#2543) - avoid excessive sort() in merge.js
(pouchdb/mapreduce#228) - fix phantomjs test

This is what's preventing the phantomjs
tests from running in Travis for express-pouchdb
and pouchdb-server.
Merge remote-tracking branch 'upstream/master' into pull-replication-test
Re-activating tests and clean up