Merge remote-tracking branch 'origin/master'

Conflicts:
	src/finproject/Road.java
	src/finproject/RoadIterator.java

planning for building proposal

priority queue, proposal graph, roads
now have isBuilt filed
priority queue, proposal graph
Merge remote-tracking branch 'origin/master'

Conflicts:
	src/finproject/Graph.java
	src/finproject/Road.java
	src/finproject/RoadIterator.java