message: Lowers the minimum required version of boost from 1.57 to 1.54.
  Version 1.54 is available on BG/Q, so users could avoid managing their own copy, if desired.
  Misc: Removed the ENABLE_BOOST option since we are now using BOOST_DIR (and it had a typo).
diff: # (Standard Boost Include dirs)
  # set the vars that the standard cmake boost logic needs
  -set(ENABLE_BOOT ON)
  set(BOOST_ROOT ${BOOST_DIR})
  # find boost
  find_package(Boost
  - 1.57
  + 1.54
  REQUIRED)
  MESSAGE(STATUS "Boost include dir: " ${Boost_INCLUDE_DIR})
  MESSAGE(STATUS "Boost version: " ${Boost_VERSION})
  +
  # this is what we used to signal boost is on in our build system
  set(BOOST_FOUND TRUE)
  