Linux 3.15 has added OFD locks, which contend with POSIX file locks
but are owned by the open file description instead of the process.
Use these in krb5_lock_file where available, for safer concurrency
behavior.

ticket: 8023 (new)

Windows does not provide the glob() functionality used to implement
the /etc/gss/mechs.d/ feature, so we must avoid compiling the
relevant code for windows.  (It would never have been called, anyway.)

Adjust the ccache/Makefile.in rules to not use '-' or '@' in
make variable names that are processed by nmake.

Also in ccache/Makefile.in, remove some latent leading whitespace that
had been previously hidden by the previous rule; this exposed some
flawed dependencies that are now removed.

Windows does not provide sys/socket.h or sys/un.h, so don't try
to include them in cc_kcm.c.

The commit which moved the KKDCP TLS support to a plugin left some
dangling references to checkhost.c byproducts in os/Makefile.in,
which can be safely removed.

Use k5-platform.h in support/json.c instead of a set of system includes;
this lets windows build the static inline helper functions therein.

Make struct k5buf less opaque and get rid of k5buf-int.h.  Make it
easy to initialize a k5buf in an error state so that it can be freed
in a cleanup handler.  Add a function k5_buf_status which returns 0 or
ENOMEM.  Remove k5_buf_data and k5_buf_len.  Rename k5_free_buf to
k5_buf_free.  Adjust all callers to match.

Create an internal pluggable interface "tls" with one in-tree dynamic
plugin module named "k5tls".  Move all of the OpenSSL calls to the
plugin module, and make the libkrb5 code load and invoke the plugin.
This way we do not load or initialize libssl unless an HTTP proxy is
used.

ticket: 7929

Check kaddr and kport, not kport twice.

[ghudson@mit.edu: clarified commit message, minor style change]

If strdup fails when copying extra tokens, we must terminate the
argument traversal before returning.

[ghudson@mit.edu: clarified commit message]

[ghudson@mit.edu: squashed with similar commits]

Include autoconf.h (either directly or via proxy) before system
headers, so that feature test macros defined there can affect the
system namespace.  Where include order was changed, eliminate some
redundant or unnecessary includes.

ticket: 7961

Take advantage of the strerror_r portability wrapper to simplify code
using it.  Remove unused macros related to strerror_r in
ldap_service_stash.c and plugins.c.

ticket: 7961

Remove code to set or reference the length fields of socket addresses
(sa_len/sin_len/sin6_len), since they aren't portable and setting them
is not required.  Remove autoconf tests for those fields which are no
longer used or which were never used.

There is one exception: in localaddr.c, we still neeed to reference
sa_len for the definition of ifreq_size on platforms which have
sa_len.  Leave that behind, along with the autoconf test which defines
SA_LEN.