Preliminary support for refinding Boost

FNALCore links/exposes Boost, so clients need these headers/libs
available. Use of CMake's INTERFACE_X properties helps to automate
this, but unless imported targets are used, which FindBoost does
not, one still has hardcoded paths in the properties.

Add check/refind of Boost and required components in top level
project config file for FNALCore.