configury: ensure wrapper static LIBS is filled properly

In core library portions of the configury (e.g., top-level
configure.ac itself), we were calling AC_CHECK_LIB and
OPAL_CHECK_FUNC_LIB to check for various libraries.

'''SIDENOTE:''' It turns out that modern Autoconf has AC_SEARCH_LIBS,
which does just about exactly what OPAL_CHECK_FUNC_LIB does.  So this
commit effectively replaces OPAL_CHECK_FUNC_LIB with AC_SEARCH_LIBS.

However, we never bothered to add these found libraries to the wrapper
compiler list of libraries used for static linking (doh!).  We've been
getting lucky for quite a while that components were adding the same
libraries to their wrapper compiler LIBS list.  

This is problematic, however, if we don't build some of these
components.  For example, Paul Hargrove noticed that if he configured
with --disable-shared --enable-static --disable-io-romio, ROMIO was no
longer adding some libraries to the wrapper LIBS list -- libraries
that just happened to also be needed by core OPAL/ORTE/OMPI layers.

The solution is not to use AC_CHECK_LIB or OPAL_CHECK_FUNC_LIB, but
use a pair of new macros:

 * OPAL_SEARCH_LIBS_CORE: a wrapper around AC_SEARCH_LIBS.  If we add
   something to $LIBS, then also add it to the wrapper list of static
   libraries.  This is the main piece of functionality that was
   wrong/missing.
 * OPAL_SEARCH_LIBS_COMPONENT: similar to OPAL_SEARCH_LIBS_CORE, but
   instead of directly adding it to the wrapper list of static
   libaries, add it to <framework>_<component>_LIBS (which eventually
   gets slurped up into the wrapper list of static libraries.  See the
   lengthy comment in config/opal_setup_wrappers.m4 near the beginning
   of OPAL_SETUP_WRAPPER_INIT() for a more detailed explanation).
   Most components did this correctly already, but one or two weren't
   right, so I implemented this second macro quite similar to the
   first and put it everywhere we already used AC_SEARCH_LIBS or
   OPAL_CHECK_FUNC_LIB.

This needs to soak for a day or two on the trunk before moving to the
v1.8 branch.

Refs #4834

cmr=v1.8.2:reviewer=ggouaillardet