* Add sprockets-rails to Gemfile

* Add sprockets-rails to Gemfile.lock

* Update show.html.haml

* Update index.html.haml

* Update admin.html.haml

* Update auth.html.haml

* Update embedded.html.haml

* Update public.html.haml

related: https://github.com/tootsuite/mastodon/commit/1236529e39a7e2534fdd34686a749b5a386c109b



Signed-off-by: lindwurm <lindwurm.q@gmail.com>

* Add InstancePresenter to expose site details

* Clean up about controller, use instance presenter

* Add helper method to return Setting.site_title

* Use site_title helper in application layout

* Use site_title value for og:site_name

"Various apps are available" is now a hyperlink

This should help federation

with YAML-defined defaults. Add admin page for editing global settings. Add "site_description"
setting that would show as a paragraph on the frontpage