[Samba] Updates to RHEL 6 compatible backport of Samba 4.0.3, with domain controller activated

[Nico Kadel-Garcia]

I've been doing some work backporting the Fedora rawshid version of
Samba 4.0.3 to work with RHEL 6. The latest updates (with some
suggested changes from others) are at:

           https://github.com/nkadel/samba4repo

The full suite for building Samba 4.0.3 on RHEL 6 is there, with all
the updated libraries and hooks to put it in a yum repository. In
particular, with some help, I've gotten it to build with domain
controller options. I'd welcome anyone with more of a mixed
environment to test it: I've started a new job that doesn't need
domain controllers, and I don't have a stack of spare Windows licensed
hosts to test with.

* Bundle updated versions of libtalloc, libldb, libtevent, etc. for RHEL 6.
* Restore SysV init scripts (Fedora rawhide relies exclusively on systemd.)
* Activate "with_dc" to compile with the domain controller.
* Include a stack of libraries for the "samba-dc-libs" toolsuite.
* Clean up the dependencies for with_dc and with_mitkrb5.
* Make clear that the "with_talloc", "with_tevent", etc. flags
actually mean "with_internal_talloc" rather than using the separately
system compiled talloc, tevent, etc. (RPM spec file syntax fis usually
based on autoconf syntax, mwaning  where "--without-talloc" would mean
"do not use tlaloc at all", and it just gets confusing.
* Resolve some older RPM version issues with handling documents that
are not installed in unexpected locations under Fedora.

I also discovered something nasty: when testing out and recompiling
this material in various iterations, the "/tmp/wafgrade tends to
get..... clutered. This is problematic if you've not allocated a lot
of space on / I'd like to actually suggest that WAFCACHE be set to be
in the build directory, not over in /tmp, and that it be cleared as
part of starting any new compilation to avoid conflicts with other
projects.

Any thoughts are welcome. The first time I d id a Samba port was way,
way back with SunOS 4.1.2....