Merge pull request #154 from matthesrieke/dev

fix issues #152 and #153
Merge pull request #156 from matthesrieke/dev

debugging statements, related to #155
add methods for pending friend requests.
set up paths in FriendsResource to get list of pending friend requests
add mongo methods to identify non-bidirectional friendships
add Resource method to decline a friend request.
remove friends bi-directional as invoked by an explicit request
Merge pull request #164 from matthesrieke/feature-pending-friend-requests

Feature pending friend requests
expose Link header with Access-Control-Expose-Headers
Merge pull request #166 from autermann/cors-link

Expose Link header with Access-Control-Expose-Headers
simplified PaginatedIterable builders
interfaces for fuelings
fueling JSON encoders
fueling decoder & guice wiring
RDF encoder for fuelings
Service extensions for fuelings / FuelingDAO
REST resource for fuelings
removed obsolete warning suppressions
use boolean instead of Boolean
MongoDB backend for fuelings