Fix incorrect parsing of FCIDUMP with complex-valued integrals

[bkesk]

The FCIDUMP format with complex-valued integrals should have format:

  V_real V_imag a b c d

and

boost::split(tok, msg, is_any_of(", \t()"), token_compress_on);

should split each line into 6 tokens, not 7, unless some unexpected whitespace character is included before V_real.