Two small fixes accumulated during a Red Hat buildout

Two fixed accumulated while building out PDAL on Red Hat 2.6.

The first patch explicitly sets the LANGUAGES property in the top-level `project` call in CMakeLists.txt. I was building out using a local compiler (not the system-wide gcc) and cmake 3.0, and w/o the explicit languages setting cmake refused to find my local compilers and instead reverted to the system-wide values. I wasn't able to track down *why* that was happening, but explicitly setting the languages in our `project` call fixed the problem. I think there's no reason *not* to set those values, so might as well set them?

The second patch includes `<memory>` in Metadata.hpp, which is needed for `shared_ptr`. Not sure why that didn't get picked up by Travis.