Bump version and soname for 5.5.0alpha.

5.5.0alpha won't be released, it's just to mark that
the branch is not for stable 5.4.x.

Once again there is no API/ABI stability for new features
in devel versions. The major soname won't be bumped even
if API/ABI of new features breaks between devel releases.
diff --git a/src/liblzma/Makefile.am b/src/liblzma/Makefile.am
index 97396c0..0751f7a 100644
--- a/src/liblzma/Makefile.am
+++ b/src/liblzma/Makefile.am
@@ -24,7 +24,7 @@
 	-I$(top_srcdir)/src/liblzma/simple \
 	-I$(top_srcdir)/src/common \
 	-DTUKLIB_SYMBOL_PREFIX=lzma_
-liblzma_la_LDFLAGS = -no-undefined -version-info 9:0:4
+liblzma_la_LDFLAGS = -no-undefined -version-info 10:99:5
 
 EXTRA_DIST += liblzma_generic.map liblzma_linux.map validate_map.sh
 if COND_SYMVERS_GENERIC
diff --git a/src/liblzma/api/lzma/version.h b/src/liblzma/api/lzma/version.h
index 7d37130..c148340 100644
--- a/src/liblzma/api/lzma/version.h
+++ b/src/liblzma/api/lzma/version.h
@@ -21,9 +21,9 @@
  * Version number split into components
  */
 #define LZMA_VERSION_MAJOR 5
-#define LZMA_VERSION_MINOR 4
+#define LZMA_VERSION_MINOR 5
 #define LZMA_VERSION_PATCH 0
-#define LZMA_VERSION_STABILITY LZMA_VERSION_STABILITY_STABLE
+#define LZMA_VERSION_STABILITY LZMA_VERSION_STABILITY_ALPHA
 
 #ifndef LZMA_VERSION_COMMIT
 #	define LZMA_VERSION_COMMIT ""