Fix SONAME issue.

CHANGES.txt

@@ -1,3 +1,14 @@
+2009-11-18 version 2.2.0a:
+
+  There is probably no reason to install this release if you have arleady
+  installed 2.2.0.
+
+  C++
+  * Bumped binary interface version number, so that installing libprotobuf.so
+    v2.2.0 doesn't break already-compiled binaries that are linked against
+    v2.1.0.  This should have happened as part of the original 2.2.0 release,
+    but somehow was missed.
+
 2009-08-11 version 2.2.0:
 
   C++

configure.ac

@@ -12,7 +12,7 @@ AC_PREREQ(2.59)
 # In the SVN trunk, the version should always be the next anticipated release
 # version with the "-pre" suffix.  (We used to use "-SNAPSHOT" but this pushed
 # the size of one file name in the dist tarfile over the 99-char limit.)
-AC_INIT([Protocol Buffers],[2.2.0],[protobuf@googlegroups.com],[protobuf])
+AC_INIT([Protocol Buffers],[2.2.0a],[protobuf@googlegroups.com],[protobuf])
 
 
 AC_CONFIG_SRCDIR(src/google/protobuf/message.cc)

src/Makefile.am

@@ -73,7 +73,7 @@ nobase_include_HEADERS =                                       \
 lib_LTLIBRARIES = libprotobuf-lite.la libprotobuf.la libprotoc.la
 
 libprotobuf_lite_la_LIBADD = $(PTHREAD_LIBS)
-libprotobuf_lite_la_LDFLAGS = -version-info 4:0:0
+libprotobuf_lite_la_LDFLAGS = -version-info 5:0:0
 libprotobuf_lite_la_SOURCES =                                  \
   google/protobuf/stubs/common.cc                              \
   google/protobuf/stubs/once.cc                                \
@@ -91,7 +91,7 @@ libprotobuf_lite_la_SOURCES =                                  \
   google/protobuf/io/zero_copy_stream_impl_lite.cc
 
 libprotobuf_la_LIBADD = $(PTHREAD_LIBS)
-libprotobuf_la_LDFLAGS = -version-info 4:0:0
+libprotobuf_la_LDFLAGS = -version-info 5:0:0
 libprotobuf_la_SOURCES =                                       \
   $(libprotobuf_lite_la_SOURCES)                               \
   google/protobuf/stubs/strutil.cc                             \
@@ -119,7 +119,7 @@ libprotobuf_la_SOURCES =                                       \
   google/protobuf/compiler/parser.cc
 
 libprotoc_la_LIBADD = $(PTHREAD_LIBS) libprotobuf.la
-libprotoc_la_LDFLAGS = -version-info 4:0:0
+libprotoc_la_LDFLAGS = -version-info 5:0:0
 libprotoc_la_SOURCES =                                         \
   google/protobuf/compiler/code_generator.cc                   \
   google/protobuf/compiler/command_line_interface.cc           \