Add an explanation of libtool -version-info to src/Makefile.am, and add an explicit -version-info 0:0:0 for all libraries.

src/Makefile.am

@@ -86,6 +86,15 @@ libXCB_la_SOURCES = \
 		xcb_list.c xcb_util.c xcb_xlib.c xcb_auth.c \
 		$(COREPROTO) $(ESSENTIAL_EXTENSIONS)
 
+# Explanation for -version-info:
+# -version-info current:revision:age
+# The library supports interface (current-age) to interface current.
+# * If you changed the source code at all, increment revision.
+# * If you add an interface, increment current and age and set revision to 0.
+# * If you change or remove an interface, increment current and set revision
+#   and age to 0.
+libXCB_la_LDFLAGS = -version-info 0:0:0
+
 BUILT_SOURCES = $(COREPROTO) $(EXTENSIONS)
 CLEANFILES = $(COREPROTO) $(EXTENSIONS)
 clean-local:
@@ -93,42 +102,81 @@ clean-local:
 
 XCB_LIBS = $(top_builddir)/src/libXCB.la
 
+# FIXME: find a way to autogenerate this from the XML files.
+
+libXCBcomposite_la_LDFLAGS = -version-info 0:0:0
 libXCBcomposite_la_LIBADD = $(XCB_LIBS)
 libXCBcomposite_la_SOURCES = extensions/composite.c extensions/composite.h
+
+libXCBdamage_la_LDFLAGS = -version-info 0:0:0
 libXCBdamage_la_LIBADD = $(XCB_LIBS)
 libXCBdamage_la_SOURCES = extensions/damage.c extensions/damage.h
+
+libXCBdpms_la_LDFLAGS = -version-info 0:0:0
 libXCBdpms_la_LIBADD = $(XCB_LIBS)
 libXCBdpms_la_SOURCES = extensions/dpms.c extensions/dpms.h
+
+libXCBglx_la_LDFLAGS = -version-info 0:0:0
 libXCBglx_la_LIBADD = $(XCB_LIBS)
 libXCBglx_la_SOURCES = extensions/glx.c extensions/glx.h
+
+libXCBrandr_la_LDFLAGS = -version-info 0:0:0
 libXCBrandr_la_LIBADD = $(XCB_LIBS)
 libXCBrandr_la_SOURCES = extensions/randr.c extensions/randr.h
+
+libXCBrecord_la_LDFLAGS = -version-info 0:0:0
 libXCBrecord_la_LIBADD = $(XCB_LIBS)
 libXCBrecord_la_SOURCES = extensions/record.c extensions/record.h
+
+libXCBrender_la_LDFLAGS = -version-info 0:0:0
 libXCBrender_la_LIBADD = $(XCB_LIBS)
 libXCBrender_la_SOURCES = extensions/render.c extensions/render.h
+
+libXCBres_la_LDFLAGS = -version-info 0:0:0
 libXCBres_la_LIBADD = $(XCB_LIBS)
 libXCBres_la_SOURCES = extensions/res.c extensions/res.h
+
+libXCBscreensaver_la_LDFLAGS = -version-info 0:0:0
 libXCBscreensaver_la_LIBADD = $(XCB_LIBS)
 libXCBscreensaver_la_SOURCES = extensions/screensaver.c extensions/screensaver.h
+
+libXCBshape_la_LDFLAGS = -version-info 0:0:0
 libXCBshape_la_LIBADD = $(XCB_LIBS)
 libXCBshape_la_SOURCES = extensions/shape.c extensions/shape.h
+
+libXCBshm_la_LDFLAGS = -version-info 0:0:0
 libXCBshm_la_LIBADD = $(XCB_LIBS)
 libXCBshm_la_SOURCES = extensions/shm.c extensions/shm.h
+
+libXCBsync_la_LDFLAGS = -version-info 0:0:0
 libXCBsync_la_LIBADD = $(XCB_LIBS)
 libXCBsync_la_SOURCES = extensions/sync.c extensions/sync.h
+
+libXCBxevie_la_LDFLAGS = -version-info 0:0:0
 libXCBxevie_la_LIBADD = $(XCB_LIBS)
 libXCBxevie_la_SOURCES = extensions/xevie.c extensions/xevie.h
+
+libXCBxf86dri_la_LDFLAGS = -version-info 0:0:0
 libXCBxf86dri_la_LIBADD = $(XCB_LIBS)
 libXCBxf86dri_la_SOURCES = extensions/xf86dri.c extensions/xf86dri.h
+
+libXCBxfixes_la_LDFLAGS = -version-info 0:0:0
 libXCBxfixes_la_LIBADD = $(XCB_LIBS)
 libXCBxfixes_la_SOURCES = extensions/xfixes.c extensions/xfixes.h
+
+libXCBxprint_la_LDFLAGS = -version-info 0:0:0
 libXCBxprint_la_LIBADD = $(XCB_LIBS)
 libXCBxprint_la_SOURCES = extensions/xprint.c extensions/xprint.h
+
+libXCBxtest_la_LDFLAGS = -version-info 0:0:0
 libXCBxtest_la_LIBADD = $(XCB_LIBS)
 libXCBxtest_la_SOURCES = extensions/xtest.c extensions/xtest.h
+
+libXCBxv_la_LDFLAGS = -version-info 0:0:0
 libXCBxv_la_LIBADD = $(XCB_LIBS)
 libXCBxv_la_SOURCES = extensions/xv.c extensions/xv.h
+
+libXCBxvmc_la_LDFLAGS = -version-info 0:0:0
 libXCBxvmc_la_LIBADD = $(XCB_LIBS)
 libXCBxvmc_la_SOURCES = extensions/xvmc.c extensions/xvmc.h