change java version number, addresses #1418

apparently the new version of Jersey/Grizzly in commit
b84d028d928d37078f89113c7e0ea986fc42af33 requires java 1.7
add comments to default wayproperties based on grant and frank's comments
comments explaining Attribute/AttributeData
rename function to reflect the difference between IDs and fully specified CSV columns, add Javadoc
store Polygons rather than Geometries
add Javadoc and log warnings for incorrect geoms, reuce code duplication
rename field to distinguish between capacity and actual number of features