Add a kdb5_util examples for old KDC upgrades

It's a slightly less-contrived use case of the utility than the
other example, which reads more like a usage statement.
Give a motivating sentence before each example, and note that this
new example is not needed in the general upgrade case.

The need to dump/load for upgrades prior to 1.2 was documented in
the texinfo install guide, but not in any RST sources until now.

ticket: 7407
Add section on updating from single-DES

There are, unfortunately, still some single-DES deployments out
there.  Try to help them along by documenting a procedure for
migrating to stronger crypto.

The texinfo install guide had a section on "upgrading", but it was
not really suitable for direct import into a RST document.  For one,
it gave a high profile to the on-disk incompatibilities in upgrades
to 1.1 and 1.2.  It also was driven at upgrading *to* triple-des (or RC4),
which are something of a dead-end.  This new text attempts to be more
general and applicable to today's environment.
Disconnect texinfo install guide from the build

Its content has been migrated to or superseded by the RST documentation,
split amongst krb_build and various sections of krb_admins.

A few portions of the texinfo document are simply no longer relevant
and do not need to be migrated.  In particular:
It's 2012; we don't need to specify that we require a C89 compiler.
It's 2012; it will be easy to get enough disk to build krb5.
The KADM5 tests are part of 'make check' and don't need separate
documentation.
Shared library support is not limited to "a few operating systems".
We do not need to document incompatibilities with ancient/dead OSes.
kadmind4 and v5passwdd are no longer relevant.

ticket: 7408
Remove make glue for texinfo install guide

Towards removing the texinfo docs entirely.

ticket: 7408
Remove unused texinfo sources

Now that the install guide make rules are removed, nothing references
build.texinfo or install.texinfo any more (other than the tgz target,
which is updated accordingly).

ticket: 7408
Fix argument order when calling the responder
Document TXT records for realm lookup

Even though they are subject to vulnerabilities via DNS spoofing
and we accordingly don't recommend their use, we do have the code
to use them.  Just as we document dns_lookup_realm in krb5.conf(5),
document them here.

ticket: 7407
Wordsmith SRV records for KDCs

Tweak the wording a bit to be more clear and avoid using multiple
words deriving from the stem "use" in close succession.
Fix slow kprop dejagnu test

Fix kpropd -S -t to actually exit after processing one connection (it
was breaking out of the switch statement, not the while loop).  Use
the -t when invoking kpropd from the dejagnu test framework;
previously it was unnecessary because kpropd -S -d exited after one
connection.  Clear up some confusion in the kprop.exp comments about
whether kpropd is expected to exit.
Wordsmith in kadm5_acl.rst

Grammar fixup and avoid jargon.
kadm5.acl line order is important

Make it a special note in the documentation to help it stand out.
Make the kadm5.acl example sane

It is an eggregious security violation to give all admin principals
admin rights and then give all null instances permission to change
the password of the associated admin instance.

While here, don't assume that admin and root are the only non-null
instances, and correct the formatting of an entry with restrictions.
Correct kadm5.acl synopsis

The target principal and restrictions arguments are not orthogonal;
a target principal argument must be given in order for a restriction
list to be supplied.
Normalize format of kadmin option descriptions

Start with a capital letter and end with a full stop, making
the description a sentence (or at least close to one).
Fix a couple of typos
Add an input ccache get-init-creds option

Add a krb5_get_init_creds_opt_set_in_ccache() function.  An input
ccache may hold configuration data which the client libraries can
use to influence their decisions.
Use octal escapes for non-printable parts of {str}/{lenstr}/{data}

When adding {str}, {lenstr}, or {data} to trace output, scan for
bytes which might be non-printable, and add them as octal-escaped
versions of themselves if any are found.
Add a -C flag to dump configuration entries
Add "pa_types" configuration to ccaches

* When producing preauth data, keep track of the types of padata which
  the module that produced the data can handle.  Originally this was
  just the type of data we'd produced, but that caused problems for
  PKINIT.
* After obtaining credentials, store that list of preauth types as a
  "pa_types" configuration item in the out_ccache.
* Read a list of allowed preauth types from an in_ccache, if possible.
* If we have a list of allowed preauth types, skip any "real" modules
  which aren't in that list.
Test in_ccache and pa_types functionality

* Add a krb5int_build_conf_principals() function to allow our get/set
  code to directly prune out duplicate config entries.
* Verify that when we specify pa_types, they affect whether or not we
  will use a particular preauth mechanism.
* Verify that we correctly save the list of preauth mechanisms that are
  used in out_ccaches.