Import of code from heimdal

Import of code from heimdal

This commit updates the code imported from heimdal to
b118610a9c56835c4ac5dc49ce8124cae8078346 (switch-from-svn-to-git-2478-gb118610)

Upstream changes are:

Harald Barth (1):
      Move common code to krb5_unsupported_enctype() and make error message contain string instead of error number

Jeffrey Altman (1):
      roken: declare IN_LOOPBACKNET if necessary

Love Hornquist Astrand (5):
      Warning fixes from Christos Zoulas
      Fixes from NetBSD via Thomas Klausner and Roland C. Dowdeswell
      Rename subsystem_DEPRECATED to subsystem_DEPRECATED_FUNCTION(X)
      remove trailing whitespace
      remove warning, remove forward declaration by moving the function up, ident

Love Hörnquist Åstrand (4):
      don't set i = 0, its never read
      sprinkle doxygen and kode more like the rest of the code base
      partly unify enctype/keytype since there is only enctypes
      switch to KRB5_ENCTYPE

Roland C. Dowdeswell (1):
      Fix a couple of bugs in krb5_c_valid_enctype():

chas williams - CONTRACTOR (1):
      hcrypto: var name current conflicts with linux kernel

Change-Id: Id9a7a9ee8258b979b54f4ed2b4175815ab35ea21
Reviewed-on: http://gerrit.openafs.org/5399
Reviewed-by: Simon Wilkinson <sxw@inf.ed.ac.uk>
Tested-by: Simon Wilkinson <sxw@inf.ed.ac.uk>
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>