Add libtool support.

libzebra and libospfapiclient are now built shared, and linked shared
with the daemons.  This reduces the memory needed when running
multiple daemons; each daemon is at least 150k smaller.  Static
libraries are still built, and libtool should use them on platforms
which don't have shared libaries.  As with autoconf, the user of a
distribution does not need libtool; one just needs that to build from
CVS.

libospf.a is still a non-shared library, and still installed, not
because that makese sense, but because I don't understand why it is
the way it is now.

Note that the tree was tagged 'libtool-before' just before this commit.
diff --git a/bgpd/Makefile.am b/bgpd/Makefile.am
index 9cb3a90..c243bfa 100644
--- a/bgpd/Makefile.am
+++ b/bgpd/Makefile.am
@@ -24,7 +24,7 @@
 bgpd_SOURCES = \
 	bgp_main.c $(libbgp_a_SOURCES)
 
-bgpd_LDADD = ../lib/libzebra.a @LIBCAP@
+bgpd_LDADD = -L../lib -lzebra @LIBCAP@
 
 examplesdir = $(exampledir)
 dist_examples_DATA = bgpd.conf.sample bgpd.conf.sample2