Necessary for RPM builds on RHEL5

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.

Fix consts and function declarations

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.

Ensures that the common libraries build statically.
Also ensures that the sssd.spec creates the SYSV init script with
the appropriate permissions.

Cleans up the useless rpmdist target that was obsolete.

Adds the *.so.N.0.0 files to the RPM, as the .so and .so.N files
were dangling symlinks.

Allow configuration and build of individual SSSD utility libraries
from their own subdirectories. Building all utilities is still
possible recursively from the common root.