Avoid bit shifting in krb5.h constants

Our traditional practice is to use hex integer literals for flag bits.
Bit shifting can be dangerous because shifting into the sign bit is
undefined.  Convert existing bit shift expressions to hex literals.
More RST rename follow-up

Update conf.py for paths to man page sources and update make rules
for building the man pages.
Correct README files for the location of the sources.
Remove nroff man pages

We generate man pages from RST sources now; they are checked into
the tree in src/man/.

The gen-manpages directory is no longer needed.
Check in kadm5.acl.man

Somehow this man page was overlooked, previously.
Regenerate man pages

Catch up to the RST content updates.

Lots of .sp vertical space macros are removed, and the output engine
spelles "restructuredText" correctly, now.
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.

ticket: 7413 (new)
Add "pa_type" configuration to ccaches

* When producing preauth data, keep track of the type of padata in the
  KDC's list of acceptable types which prompted the module to produce
  padata.
* After obtaining credentials, store that value as a "pa_type"
  configuration item in the out_ccache.
* Read that allowed preauth type from an in_ccache, if possible.
* If we have an allowed preauth type, only call "real" modules that
  handle that value when filling in responder items and producing a
  client request.

ticket: 7414 (new)
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 a pa_type, it affects whether or not we
  will use a particular preauth plugin.
* Verify that we correctly save the KDC's preauth type number, that we
  tried to answer, to the out_ccache.
Use blocking locks for policy DB

In the db2 kdb module, use blocking locks for the policy DB as well as
the principal DB.

ticket: 7359
Remove KRB5_DB_LOCKMODE_DONTBLOCK from kdb.h

It's wasn't used and wasn't implemented.
Use bulleted instead of ordinal lists as needed

The texinfo-generated NOTICE used bullets for some of the lists;
make the RST source consistent with that.
Regenerate NOTICE from RST sources

With manual postprocessing to compensate for the sphinx text output
engine mishandling line blocks.
Remove install-oldman

The old man pages are gone, so we can't install them anymore.
Also clean up install and install-unix targets that were installing
the old man pages by hand.
Install missing man pages

Add kadm5.acl, sserver, and sclient to MANSUBS so that we will install
them in the normal build process.
Make rules for missing man/catpages

Add the make rules to install the subfiles as man and cat pages,
missed in the previous commit.

Also correct the omission of catpages for the server binaries.
Add docs for kinit's -I option
Regen kinit.man from RST sources

To pick up the -I option.
Add "pa_config_data" configuration to ccaches

* Read a "pa_config_data" item from an in_ccache, if provided, and add a
  callback which client preauth plugins can use to retrieve a string
  value from it that's keyed by a string.
* Add a callback which client preauth plugins can use to provide string
  key/value pairs to be stored in the ccache.
* Moves the definition of (struct krb5_clpreauth_rock_st) from k5-int.h
  to init_creds_ctx.h to try to reduce the number of files that will
  need to include k5-json.h to understand k5_json_value.
Use config storage for client identity selection

* Keep track of the names of client identities when we load them.
* Store the client identity we just used when we create or retry a
  client request.
* If we read a client identity from the configuration, treat it like the
  KDC does: pick the "this is it, there is no other" logic branch.
Fix kswitch section heading markup

SYNOPSIS is a first-level section, and should use '-' like the other
sections.