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

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

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)

add MVAPICH2 easyblock (tested with GCC 4.6.3 and MVAPICH v1.7) and example .eb spec file in easyconfigs

add easyconfig for BLACS: .eb spec file with GCC 4.6.3 and OpenMPI 1.4.5 and patch file to enable configuring the build

Merge branch 'master' of ssh://savannah.ugent.be/savannah/git/source/easybuild/easybuild1 into 103_toolkit

improved file_locate function to search for files in different locations, e.g. sources in easyblocks-style and patch files also in easyconfigs subdir (refs #229)

add easyconfig for GCC (.eb spec files for GCC v4.5/4.6/4.7 with and without CLooG/PPL support + patch for mpfr 3.1.0)

tested with GCC v4.5/4.6/4.7 both with and without CLooG/PPL support;
various other improvements/bugfixes along the way

adjust setup scripts so it creates both the easyblocks and easyconfigs directories, squash the '_other_' and '0-9' easyblocks subdirs into '0' (refs #125)

adjust setup scripts so it creates both the easyblocks and easyconfigs directories, squash the '_other_' and '0-9' easyblocks subdirs into '0'

add strict version check for lower than v4.5 and option to skip with skipversioncheck, warn when building with 4.8 or higher

get rid of code that sets C_INCLUDE_PATH, LD_LIBRARY_PATH and LD_RUN_PATH for GMP, since it makes no difference w.r.t. the __gmp_get_memory_functions undefined references (real problem was that path of other libgmp.so was present in LD_LIBRARY_PATH)

add support to make LTO fully optional (required for GCC v4.5 build without libelf installed)