DRY

In #6603 hovercards were activated for logged out users, but they only
worked for local people. Hovercards on remote-people are important to
get the diaspora-id to search the person on the local pod, if you don't
know who it is.

Updates introduce support for preloading contacts to Gon in order
to support client-side rendering of aspect membership dropdown box.

in order to support adding new aspect to a dropdown without full
page reload

closes #6603

closes #6398

This adds a new boolean field "public_details" to person model.
By default it is false and represents old behaviour. When it is
set to true, extended profile (bio,location,gender,birthday)
get available to people who didn't log into diaspora and to
people you don't share with (i.e. it is made public).

In UI, a bootstrap-switch added on the profile-edit page in order to
change the setting.

This also changes wording from public/private profile to basic/extended.
The latter could be public and limited.

related to diaspora/jsxc#77

* re-add stream on profile page
* more controller refactoring

* added handlebars helper for markdown formatting
* finished port of profile sidebar view to handlebars template
* people_controller refactoring

* include 'js-routes' for rails routes in javascript
  (TODO: config options?)
* add handlebars helper for rails routes

* introduce new presenters and extend the functionality of the BasePresenter
* add a handlebars template for the profile sidebar, render it everytime we need to update
* introduce a 'aspect_membership:update' global event

  Fix issue #4951

  If the displayed user (on her profile) started sharing with the
current user, mark the notification as read

Added search_controller_spec, moved some tests from people_controller_spec to search_controller_spec

Fixed merged conflict in Changelog

update routes and search controller

remove useless except from search controller

Fix indentation in search_controller

* Rename and reorganize post fetcher to fix autoloading, also let it use
  Faradays default connection so we get nice redirects
* Add initializer to load libs at a central place
* added lib dir to autoload_once paths to increase thread safety
* Moved lib/exceptions.rb to lib/diaspora/ to conform namespacing