autoconf: Split PACKAGE_VERSION in four parts

The parts can be accessed with the variables:

	PACKAGE_VERSION_MAJOR
	PACKAGE_VERSION_MINOR
	PACKAGE_VERSION_BUILD
	PACKAGE_VERSION_REVIEW

The last part will be empty for regular releases.

configure.ac

@@ -27,6 +27,9 @@ AC_CONFIG_HEADERS([config.h])
 AC_DEFINE([CONFIG_H_INCLUDED], [], [defined if config.h included])
 PKG_PROG_PKG_CONFIG
 
+m4_include(m4/macros/split-package-version.m4)
+SPLIT_PACKAGE_VERSION
+
 # =================================
 #  check --enable-xxx & --with-xxx
 # =================================

m4/macros/split-package-version.m4

@@ -0,0 +1,17 @@
+# SPLIT_PACKAGE_VERSION
+# ---------------------------
+# Split package version in four parts
+AC_DEFUN([SPLIT_PACKAGE_VERSION],
+	[
+	AC_REQUIRE([AC_PROG_SED])
+	PACKAGE_VERSION_MAJOR=`echo "$PACKAGE_VERSION" | $SED 's/\([[0-9]]\+\).*/\1/'`
+	PACKAGE_VERSION_MINOR=`echo "$PACKAGE_VERSION" | $SED 's/[[0-9]]\+\.\([[0-9]]\+\).*/\1/'`
+	PACKAGE_VERSION_BUILD=`echo "$PACKAGE_VERSION" | $SED 's/[[0-9]]\+\.[[0-9]]\+\.\([[0-9]]\+\).*/\1/'`
+	PACKAGE_VERSION_REVIEW=`echo "$PACKAGE_VERSION" | $SED 's/[[0-9]]\+\.[[0-9]]\+\.[[0-9]]\+\(.*\)/\1/'`
+	AC_SUBST([PACKAGE_VERSION_MAJOR])
+	AC_SUBST([PACKAGE_VERSION_MINOR])
+	AC_SUBST([PACKAGE_VERSION_BUILD])
+	AC_SUBST([PACKAGE_VERSION_REVIEW])
+	]
+)
+