beginnings of new UX for status open bounty
* manage repos view changes
* new header + tabs style
* flash/error messages as modal overlay
* SOB favicon
* general css changes
* require only user:email oauth scope when signing up
* if user wants to set bounties on repos, request additional oauth
scopes
* do not store github access tokens on server side and use client-side
localStorage instead
Fixes: #35Fixes: #40
* removed old swing JEditorPane based html to png rendering due to
it's lack of support for modern css
* new implementation uses wkhtmltoimage (on prod server via wrapper
script using xvfb)
* no longer generating image on every GET request for QR, but rather
generating image when a bounty is cretaed or contract balance
changes
* images stored to DB
* comment image design updated according to UI spec
* semantic UI + less based UI styling
* header, tabs, user-profile component
* store avatar URL in DB, show image in user
* unify :user and :user-profile in app-db for simplicity
