debian: move libraries into separate packages

* debian/control (libbddx-dev, libbddx0, libspot0): New packages.
(libspot-dev): Make it "Architecture: any".
* debian/libspot-dev.install: Include the .so symlink.
* debian/spot.install: Remove the libraries.
* debian/libbddx-dev.install, debian/libbddx0.install,
debian/libspot0.install: New files.
* Makefile.am: Distribute them.

Makefile.am

@@ -33,12 +33,25 @@ SUBDIRS = buddy lib src wrap ltdl iface doc $(NEVER_BENCH)
 UTF8 = utf8/doc/ReleaseNotes utf8/doc/utf8cpp.html utf8/utf8.h	\
   utf8/utf8/checked.h utf8/utf8/core.h utf8/utf8/unchecked.h
 
-DEBIAN = debian/changelog debian/changelog.in debian/compat		\
-  debian/control debian/copyright debian/docs debian/rules		\
-  debian/python3-spot.examples debian/python3-spot.install		\
-  debian/source/format debian/spot-doc.docs debian/spot-doc.install	\
-  debian/spot-doc.doc-base debian/spot.install				\
-  debian/libspot-dev.install
+DEBIAN =					\
+  debian/changelog				\
+  debian/changelog.in				\
+  debian/compat					\
+  debian/control				\
+  debian/copyright				\
+  debian/docs					\
+  debian/libbddx0.install			\
+  debian/libbddx-dev.install			\
+  debian/libspot0.install			\
+  debian/libspot-dev.install			\
+  debian/python3-spot.examples			\
+  debian/python3-spot.install			\
+  debian/rules					\
+  debian/source/format				\
+  debian/spot-doc.doc-base			\
+  debian/spot-doc.docs				\
+  debian/spot-doc.install			\
+  debian/spot.install
 
 debian/changelog: configure.ac
 	$(top_builddir)/config.status --file debian/changelog