Prefix subprojects with 'smack-'

instead of using the old baseName=smack appendix=project.name approach,
we are now going convention over configuration and renaming the
subprojects directories to the proper name.

Having a prefix is actually very helpful, because the resulting
libraries will be named like the subproject. And a core-4.0.0-rc1.jar is
not as explicit about what it actually *is* as a
smack-core-4.0.0-rc1.jar.

SMACK-265

smack-resolver-dnsjava/build.gradle

@@ -0,0 +1,9 @@
+description = """\
+DNS SRV with dnsjava
+Use dnsjava for DNS SRV lookups. For platforms that don't provide the
+javax.naming API (e.g. Android)."""
+
+dependencies {
+	compile project(path: ':smack-core', configuration: 'dns')
+	compile 'dnsjava:dnsjava:2.1.+'
+}

smack-resolver-dnsjava/src/main/java/org/jivesoftware/smack/util/dns/DNSJavaResolver.java

@@ -0,0 +1,66 @@
+/**
+ *
+ * Copyright 2013-2014 Florian Schmaus
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smack.util.dns;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.xbill.DNS.Lookup;
+import org.xbill.DNS.Record;
+import org.xbill.DNS.TextParseException;
+import org.xbill.DNS.Type;
+
+/**
+ * This implementation uses the <a href="http://www.dnsjava.org/">dnsjava</a> implementation for resolving DNS addresses.
+ *
+ */
+public class DNSJavaResolver implements DNSResolver {
+    
+    private static DNSJavaResolver instance = new DNSJavaResolver();
+    
+    private DNSJavaResolver() {
+    }
+    
+    public static DNSResolver getInstance() {
+        return instance;
+    }
+
+    @Override
+    public List<SRVRecord> lookupSRVRecords(String name) throws TextParseException {
+        List<SRVRecord> res = new ArrayList<SRVRecord>();
+
+        Lookup lookup = new Lookup(name, Type.SRV);
+        Record recs[] = lookup.run();
+        if (recs == null)
+            return res;
+
+        for (Record record : recs) {
+            org.xbill.DNS.SRVRecord srvRecord = (org.xbill.DNS.SRVRecord) record;
+            if (srvRecord != null && srvRecord.getTarget() != null) {
+                String host = srvRecord.getTarget().toString();
+                int port = srvRecord.getPort();
+                int priority = srvRecord.getPriority();
+                int weight = srvRecord.getWeight();
+
+                SRVRecord r = new SRVRecord(host, port, priority, weight);
+                res.add(r);
+            }
+        }
+
+        return res;
+    }
+}