configure: darwin: Change dylib install names to include major version.

This will cause linkers to link against the major lib names, instead of the
base names, allowing multiple major versions of the libraries to co-exist.
Signed-off-by: Diego Biurrun <diego@biurrun.de>

configure

@@ -2462,7 +2462,7 @@ case $target_os in
         enable malloc_aligned
         gas="gas-preprocessor.pl $cc"
         enabled ppc && add_asflags -force_cpusubtype_ALL
-        SHFLAGS='-dynamiclib -Wl,-single_module -Wl,-install_name,$(SHLIBDIR)/$(SLIBNAME),-current_version,$(LIBVERSION),-compatibility_version,$(LIBMAJOR)'
+        SHFLAGS='-dynamiclib -Wl,-single_module -Wl,-install_name,$(SHLIBDIR)/$(SLIBNAME_WITH_MAJOR),-current_version,$(LIBVERSION),-compatibility_version,$(LIBMAJOR)'
         enabled x86_32 && append SHFLAGS -Wl,-read_only_relocs,suppress
         add_ldflags -Wl,-dynamic,-search_paths_first
         SLIBSUF=".dylib"