Get the list of NeoEdge pointing to self

Edges are loaded lazily

Property definitions

neo4j $ NeoNode :: in_edges
	# Get the list of `NeoEdge` pointing to `self`
	#
	# Edges are loaded lazily
	fun in_edges: List[NeoEdge] do return internal_in_edges or else load_in_edges
lib/neo4j/neo4j.nit:623,2--626,78