* Fix regressions from #2683

Properly format spoiler text HTML, while keeping old logic for blankness intact
Process hashtags and mentions in spoiler text
Format spoiler text for Atom
Change "show more" toggle into a button instead of anchor
Fix style regression on dropdowns for detailed statuses

* Fix lint issue

* Convert spoiler text to plaintext in desktop notifications

* fix character escaping in URL

* add tests

* put a comma after the last item

* add HTML escape test

Try to fix Travis CI setup

affected, replaced onClick handler with onMouseUp/Down to detect text
selection not trigger onClick handler then

to sign in page after sign up instead of root path which redirects to /about

as well as formatting of content