All files formerly in common are now being built individually out
of the ding-libs repository.

git clone git://git.fedorahosted.org/git/ding-libs.git

This patch:
1) Adds the definition of the metadata interface
to the header file. The functions that were exposed
for no good reason are now hidden.
2) Previously exposed functions and their descriptions
are removed from the public header and placed into
the source code for now.
3) The function that reads the config file no longer
tries to close file in case of error.
4) Lines collection is still passed in into the reading
function but as a collection itself not as a pointer
to it.
5) All the parts related to processing lines are currently
ifdefed using HAVE_VALIDATION that is currently is not defined.
This is done to disable creation of the lines collection
utill it is actually needed. I did not want to blindly remove
it though and loose already done work that will be useful
in future.
6) Version of the library and interface is updated
7) New header and source modules are introduced to hold functions
related to the meta data. They are mostly stubbed out.

This is incomplete patch. It builds and make check runs.
It is created just to simplify the review a bit.

Added configurable key length.
Changed comments for the functions that
are currently not used and reserved for
future functionality.

- replaced mailing list address
- let sssd base components read version from VERSION

Previously, only the SSSD server components were being built with
compile-time warnings enabled. This patch will ensure that all
components in common and sss_client are also built the same way.

If automake 1.11 or higher is available, use of the configure
option '--enable-silent-rules' will suppress most build messages
and replace them with lines such as
CC   sysdb.o

This affects libtool as well.

LT_INIT is supported only on Libtool >= 2.0, so I reverted it to
using AC_PROG_LIBTOOL.

Also reorganized how the common libraries were being built. Now
they are treated as libtool convenience libraries instead of
installable libraries (the --with-singlelib configure flag can
still be used to generate a combined, installable DSO)

I cleaned up the set of files being installed by automake, so the
list of things we need to remove before packaging the RPM is now
only the .la files associated with our own plugins.