please unblock FAI 3.1.7

[Thomas Lange <lange@informatik.uni-koeln.de>]

Hi release team,

I like to ask you to unlock FAI 3.1.7.
If fixes two important bugs (see bug numbers below), and includes two
documentation fixes.

  * subroutines: ifclass() should append to stderr (closes: #409059)
  * examples/simple/, lib/fai-mount-disk, lib/mount2dir: use bash for
    shell scripts (closes: #410084)  
  * fix typo in bug number of older changelog entry
  * install_packages.8: add info for variable MAXPACKAGES

-- 
regards Thomas