Note: Unfortunately this does not fix the catastrophic compiler errors
that ifort 12 also produces.

...not tested at the moment.

+integrate weights array into t_cdnvalJob type

(at the moment this is broken)

Xc pot refactor finished (libxc GGA is missing)

See merge request fleur/fleur!3

# Conflicts:
#   types/types.F90

Some preparations for libxc GGA implementation. Still not working. Additional derivative has to be implemented....