Move ST_PlanarGraph test to its own class.
Rename GraphBuilderTest -> ST_GraphTest
Format testST_Graph()
Format testZGraph()
Format testZGraph2()
Format testDim3()
Small refactor
Update javadoc
Use simpler numbers
Small simplifications
Remove object reference switching; update tests.
Clean up tests
Add missing close.
Merge pull request #47 from agouge/fix/pre-#27

Initial cleanup of NetworkGraphBuilder and ST_Graph tests.