implemented on click listeners for pending invites
finished all ui, added database
added pending friend invitations activity
Merge pull request #4 from dainiuss/001_ui_fixes

added pending friend invitations activity
added friends view and invitation view
Merge pull request #5 from dainiuss/002_pending_invitations_remove

added friends view and invitation view, added invites remove on click functionality
Merge pull request #6 from dainiuss/development

Completed FriendsView