Fix tests for missing LIBGEOTIFF.
Port Decimation filter
Merge pull request #625 from PDAL/move-decimation-filter

Port Decimation filter
Port Ferry filter
Merge pull request #626 from PDAL/move-ferry-filter

Port Ferry filter
Merge branch 'master' into drivers-to-io

Conflicts:
	src/CMakeLists.txt
	test/unit/CMakeLists.txt
catch up drivers->io rename to master