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

refactor out get_mpilib_specifics function in BLACS easyblock, because it can also be used in ScaLAPACK

added easyconfigs for FFTW, LAPACK and ATLAS

implemented easyblock for ATLAS, which allows ignoring CPU throttling check and building against netlib's LAPACK to make ATLAS provide a full LAPACK lib; building shared libs is optional
also added example .eb spec files and two important patches (fix make install for shared libs, fix illegal instruction error)

add cleaned-up and tested easyblock for LAPACK, and example .eb in easyconfigs for building LAPACK without BLAS, with ATLAS as BLAS lib, and in test_only mode (for e.g. testing BLAS and LAPACK libs after building ATLAS with LAPACK provided)

add .eb spec file for FFTW 3.3.1 built with GCC 4.6.3 and OpenMPI 1.4.5 (without OFED support) to easyconfigs

Removed dependency on setuptools by using extend_path for namespace packages instead of pkg_resources.declare_namespace

fix easyblocks namespace, recommend setuptools for pkg_resources module, limit output on failed build (refs #125 refs #7)

tested OpenMPI build;
added easyconfigs for MVAPICH2, BLACS and OpenMPI;
fixed various issues in new structure, and working with a fresh Python installation (e.g. without a pkg_resources module)
(refs #125 refs #7 refs #103)

MVAPICH2 easyblock: make sure a previous installation directory is removed, as it might lead to confusing errors (e.g. when the previous build was done with checkpointing enabled and the BLCR libs were removed before the new build);
added custom sanity check for MVAPICH2

add cmd_prefix option to configure, fix getting easyblock instance after getting rid of _other_ and renaming 0-9 to 0

add check for pkg_resources availability in __init__ of easybuild and easyblocks, so EasyBuild tells you instead of always defaulting to Application (refs #125)