Implement activity chooser.

When for given intent there are multiple activities,
it will use activity chooser to let user decide which one to use.
Let user cancel intent from activity chooser.
Delete unnecessary files and styles
Get styling back for ingest screens

Change class names no to conflict with list -view directive
Fix styling in ingest/archive view

Fix action buttons styling
Fix archiving status and mark
Shadow for scroll elements

Add directive to show top-shadow on scroll elements
Make direct use of activityChooser service in directive view.
Merge Petrs branch - activity chooser
Add styling for activity chooser
Merge Petrs changes
Fix users listing via using superdesk.data provider.
Merge remote-tracking branch 'nikola/templating'