Making more headers installable

Ran into issues trying to use folly.  Traced it back to certain headers not being installed to /usr/local/include.  I'm not sure if this is the appropriate solution or not.  Would love feedback.

Problem: After installing folly, inclusion of certain headers lead to compliation errors (e.g. Conv.h complained of not being able to find CpuId.h).
Solution: Install headers that have come into existence since the last major update to Makefile.am.