Update to libxc version 2.0, reset 2 regtest (introduction of cutoff).
Version libxc 1.2 will no longer work!
You have to update the ARCH file to __LIBXC2.
Fabien Tran


git-svn-id: svn://svn.code.sf.net/p/cp2k/code/trunk@12652 bac0169d-1eea-4375-b5f6-f89d2ced9994