Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Fix conflicts after heimdal-1.1 import and add build infrastructure. Import
all non-style changes made by heimdal to our own libgssapi.

style.Makefile(5).

OK'ed by: nectar

Overhaul of kerberos5/ makefiles. Most significant changes are:

- Dropped support for standalone builds, this was only partially
supported anyway, and required so much magic in makefiles that
made life dangerous (e.g., by using the custom yacc rules).

- Got rid of .OBJDIR in makefiles -- makes building of individual
files possible again.

- Made the .x.c transformations -j safe.

- Reprogrammed LDADD to fix static build of some utilities that
was broken.

- Fixed LDFLAGS and DPADD in the WITH_OPENLDAP case -- positively
affects the contents of .depend files.

- Removed redundant .h's from SRCS, only kept those that are
generated.

- libkrb5/ INCS were bogusly installed again with libgssapi/.

- Made build-tools real tools with their own makefiles in
separate directories. This allows us to properly track
their dependencies, etc.

- Faster build, 21% less of makefile code!

Approved by: nectar
Reviewed by: markm
Silence on: arch

Build and install the verify_krb5_conf(8) utility, which checks
krb5.conf(5) for obvious errors.