[pdal] Windows works

[Michael P. Gerlek]

We're up and running again!

I've resolved the various remaining bits of fallout from the embedded boost work, made some updates to the build instructions, and updated a couple unit tests so that we now build and run cleanly now on Windows (158 tests passing).

The "supported" Windows build configuration is that of the "Basic Build Steps" instructions at http://www.pointcloud.org/building/windows.html. This build uses an unmodified config.bat file, OSGeo4W's gdal-dev and laszip, cmake 2.8.7, and embedded boost (natch).

-mpg