Updates several modules to use ftp_utils

* springer_package

* oup_package

* scoap3utils

* springer_package

* contrast_out

* elsevier_package

* ftp_utils: adds delete, get_filesize,
  mkdir, rmdir, upload and check_pkgs_integrity
  functions.

* ftp_utils: ammends __init__ to support login
  with netrc files.

Signed-off by: Georgios Papoutsakis<georgios.papoutsakis@cern.ch>