NeighborListCache: added implementation.

NeighborListCache fix: should not add ourselves to our neighborlist.

NeighborListCache: fixed memory leak.

NeighborListCache: cosmetics.

NeighborListCache: fixed an uninitialized ptr.
QuadTree: added implementation.

QuadTree: improvements, added move() function, comments, etc.

QuadTree: added staticNetwork param.
NeighborCaches: merge fixes.

IdealMac & AODVRouting: fixed merge errors.
NeighborCaches: removed scenario-specific default values.
NeighborCaches: added examples.
QuadTreeNeighborCache: separated the data structure.
util/QuadTree: added implementation.