give command line config file preference over enviroment variable EASYBUILDCONFIG, minor tweaks to default config and error reporting

determine toolkit dependencies based on module file instead of loaded modules, add support for this (show, dependencies_for) in tools/modules.py (closes #245)

determine toolkit dependencies based on module file instead of loaded modules, add support for this (show, dependencies_for) in tools/modules.py

fix moduleclass in example .eb spec files, shorten ATLAS description, add custom sanity check paths for OpenMPI (refs #108)

fix moduleclass in example .eb spec files, shorten ATLAS description, add custom sanity check paths for OpenMPI

make sure all easyblocks paths (which are listed in PYTHONPATH) are checked when trying to find an easyblock (refs #246)

make sure all easyblocks paths (which are listed in PYTHONPATH) are checked when trying to find an easyblock (refs #246)

ement easyblock for HPL (based on old HPCC easybuild support), and add example .eb spec file for HPL to easyconfigs (refs #108)

implement easyblock for HPL (based on old HPCC easybuild support), and add example .eb spec file for HPL to easyconfigs (refs #108)

fixed detection of toolkit dependencies by also taking previously loaded modules into account (refs #245)

implemented by refactoring and extending tools/toolkit.py and added loaded_modules function to tools/modules.py
tested with goalf toolkit (refs #103)

Conflicts:
	easybuild/framework/application.py

add easyblock for compiler toolkits (Toolkit), add example .eb spec file for goalf toolkit, i.e. version 1.1.0 (GCC 4.6.3, OpenMPI 1.4.5, ATLAS 3.8.4, LAPACK 3.4.0, FFTW 3.3.1 and ScaLAPACK 1.8.0 (with BLACS 1.1)

also add example .eb spec files for versions 1.8.0 and 2.0.1 with GCC 4.6.3, etc

revert using external function for determining MPI library specific stuff, can't be used for ScaLAPACK anyway