reformat long method comments
reformat method comments to 80 columns
document IsPath requires non-nil graph
add IsPath tests
break comments at 100 columns
Updated top-level interface
Cleaned up mutable graph
Updated cost functions
Updated mutablegraph again
Updated gonum graph
Gofmt'd renamed edge and node
Gofmt'd renamed edge and node
Cleaned up TileGraph
Removed empty tests from gonumgraph_test
Removed coverage tests from tilegraph_test
Updated tests
Updated internal functions
Fixed redundant declaration
Updated FloydWarshall
Converted main graph searched to use new edge API