message: Less annoying cmake output
diff: # Written by Hannes Hofmann <hannes.hofmann _at_ informatik.uni-erlangen.de>
  # Improvements by Gino van den Bergen <gino _at_ dtecta.com>,
  # Florian Uhlig <F.Uhlig _at_ gsi.de>,
  -# Jiri Marsik <jiri.marsik89 _at_ gmail.com>
  +# Jiri Marsik <jiri.marsik89 _at_ gmail.com>,
  +# Stefan Zellmann <info _at_ szellmann.de>,
  # The MIT License
  #
  @@ -156,7 +157,7 @@ if (NOT _TBB_INSTALL_DIR)
  endif (NOT _TBB_INSTALL_DIR)
  # sanity check
  if (NOT _TBB_INSTALL_DIR)
  - message ("ERROR: Unable to find Intel TBB install directory. ${_TBB_INSTALL_DIR}")
  + message (STATUS "Unable to find Intel TBB install directory. ${_TBB_INSTALL_DIR}")
  else (NOT _TBB_INSTALL_DIR)
  # finally: set the cached CMake variable TBB_INSTALL_DIR
  if (NOT TBB_INSTALL_DIR)
  @@ -265,7 +266,7 @@ if (TBB_INCLUDE_DIR)
  endif (TBB_INCLUDE_DIR)
  if (NOT TBB_FOUND)
  - message("ERROR: Intel TBB NOT found!")
  + message(STATUS "Intel TBB NOT found")
  message(STATUS "Looked for Threading Building Blocks in ${_TBB_INSTALL_DIR}")
  # do only throw fatal, if this pkg is REQUIRED
  if (TBB_FIND_REQUIRED)
  