Merge branch '1818_refactoring_no_vfs'

Merge branch '1818_refactoring_no_vfs'

* 1818_refactoring_no_vfs:
  Fixup of conditions for networking VFS.
  Changes for configure and build with samba:
  VFS: cleaned up smbfs.
  VFS: fishfs can now be switched off
  VFS: ftpfs can now be switched off
  VFS: extfs can now be switched off
  VFS: sfs can now be switched off
  VFS: tarfs can now be switched off
  VFS: cpiofs can now be switched off
  Type accuracy in undelfs vfs.
  undelfs now switched off by default
  VFS: fixups of UNDELFS VFS switch on/off.
  Cleanup of lib/vfs/mc-vfs/Makefile.am file.
  VFS: Type accuracy in netutil.[ch].
  VFS: Moved vfs_split_url() function from netutil.c into utilvfs.c.
  Some reorginizing of VFS private and public APIs.
  Added type for VFS class flags.
  Bug: if VFS is disabled, perl is not checked and man2hlp doesn't work.
  Ticket #1818: refactoring of VFS building options.