avoid double logging by sending output of root logger to /dev/null

self.tk doesn't exist

fix BLACS and ScaLAPACK build

fix logging issues + cleanup

fix BLACS and ScaLAPACK build: introduce gompi toolkit so that OpenMPI is a direct toolkit dependency, and adjust ATLAS, BLACS, FFTW, LAPACK, ScaLAPACK and goalf toolkit easyconfigs accordingly

336 devel module

self.tk no longer exists

fix logging issues by setting default log level for root logger as well
rename some functions in toolkit.py (consistency)
introduce toolkit_name() and toolkit_version() functions and use them