boost: better hack for boost_python (use a template to replace libboost-chrono-xyz -> libboost_python-xyz)
clhep: honor --with-clhep to detect clhep-config
compiler: add --with-xyz-compiler options to specify which compiler to use (in addition to the usual CC=xyz env.vars setup)
gccxml: honor --with-gccxml option to detect gccxml
lcgcmt -> lcg. ground work for automatically detecting the whole LCG toolchain