* cp2k: prettify arch-file, call pkg-config directly
this allows to re-use the arch-file without having to load the complete
Spack environment, for example after a dev-build
* cp2k: use consistency check instead of blas lib enum
this makes using other BLAS/LAPACK implementations possible without
explicitly adding support for them
* cp2k: add basic support for Cray and XL Compilers, correct Intel fp mode
* cp2k: add myself as maintainer
* cp2k: use "master" to denote the git version
* cp2k: use spack_cc/fc/cxx when possible, set CXX explicitly
* cp2k: set __MKL when using the MKL, not just the Intel compiler
* cp2k: drop self. when referencing spec where possible
* cp2k: add forgotten elpa+openmp dep
* cp2k: set C++14 for recent versions