Specify languages in cmake project

If languages aren't specified, they *should* default to CXX and C, but
on a cmake 3.0.2 build on Red Hat the lack of explicit languages caused
cmake to not find my local gcc/g++ install and instead use the system
compilers. Very weird, I know, but this fixed the problem, I guess
there's no harm in explicitly stating the languages?
Metadata.hpp needs a <memory> include

I'm not sure why this wasn't picked up by Travis, but build failed on
red hat due to missing <memory> include.
Port Colorization filter
Port ALL kernels
remove extraneous clearing of PDAL_TARGET_OBJECTS
missed rename of Support to KernelSupport
remove cruft, fPIC seems to be required for Kernel common object library
Merge pull request #632 from gadomski/red-hat-build-fixes

Two small fixes accumulated during a Red Hat buildout
Merge pull request #635 from PDAL/move-colorization-filter

Port Colorization filter
Merge pull request #636 from PDAL/move-kernels

Move kernels
Remove dangling references to drivers, mostly in the plugins
Merge pull request #637 from PDAL/plugin-renames

Remove dangling references to drivers, mostly in the plugins
remove remaining refernces to boost standard integer types
sudo the ctest call to avoid segfault on travis
still need sudo for make install though
Merge pull request #638 from PDAL/remove-boost-cstdint

remove remaining refernces to boost standard integer types
cleanups related to #637
Merge branch 'master' of github.com:PDAL/PDAL