Bump MiniDNS to 0.3.0-alpha1

Also add minidns-core as dependency to smack-core. This requires
increasing the minimum required Android SDK level to 9, as this is
what MiniDNS requires.

version.gradle

@@ -3,6 +3,7 @@ allprojects {
 		shortVersion = '4.3.0-beta2'
 		isSnapshot = true
 		jxmppVersion = '0.6.0'
-		smackMinAndroidSdk = 8
+		miniDnsVersion = '0.3.0-alpha1'
+		smackMinAndroidSdk = 9
 	}
 }