JTS 1.7.1 released

This is primarily a bug fix release. Changes include:

Functionality Improvements
Added Hex string conversion to WKBReader and WKBWriter

Bug Fixes
Fixed null point cloning bug in TopologyValidationError (thanks to Markus Gebhard)
Fixed bug in PointLocator fix for LinearRings
Fixed bug in Geometry.isValid and IsValidOp causing some valid polygons to be reported as having a Disconnected Interior (specifically, polygons containing holes touching at a single point, where the point is the highest point in the hole rings, and where the holes have a specific orientation)
Fixed bug in Polygon.isRectangle, which reported some valid rectangles as false

Performance Improvements
Improved performance for Geometry#withinDistance (via short-circuiting)