- DoubleBits misregards BYTE_ENDIAN, must check it.

- Have IsValidOp handle all possible exceptions thrown by
  GeometryGraph constructor (currently only with Polygon this
  is true).

- polygonizer still failing (Envelope comparison again ?)

- Add distinct binary predicates test support in XMLTester

- IsValidTest.cpp in source/test ?

- Check how to disable GEOS_VERSION define on command line
  (or make GEOS_VERSION define in version.h optional)
  not a major problems, just makes the compiler issue some warninigs.

- Check GeometryEditor behaviour (modify passed geom or create a new one ?)
  [not documented]

- Remove all explicit heap allocations for private static members.