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-javax/build.gradle

@@ -0,0 +1,8 @@
+description = """\
+DNS SRV with Java7
+Use javax.naming for DNS SRV lookups. The javax.naming API is availabe in JavaSE
+since Java7."""
+
+dependencies {
+	compile project(path: ':smack-core', configuration: 'dns')
+}

smack-resolver-javax/src/main/java/org/jivesoftware/smack/util/dns/JavaxResolver.java

@@ -0,0 +1,92 @@
+/**
+ *
+ * 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.Hashtable;
+import java.util.List;
+
+import javax.naming.NamingEnumeration;
+import javax.naming.NamingException;
+import javax.naming.directory.Attribute;
+import javax.naming.directory.Attributes;
+import javax.naming.directory.DirContext;
+import javax.naming.directory.InitialDirContext;
+
+import org.jivesoftware.smack.util.DNSUtil;
+
+/**
+ * A DNS resolver (mostly for SRV records), which makes use of the API provided in the javax.* namespace.
+ * 
+ * @author Florian Schmaus
+ *
+ */
+public class JavaxResolver implements DNSResolver {
+    
+    private static JavaxResolver instance;
+    private static DirContext dirContext;
+    
+    static {
+        try {
+            Hashtable<String, String> env = new Hashtable<String, String>();
+            env.put("java.naming.factory.initial", "com.sun.jndi.dns.DnsContextFactory");
+            dirContext = new InitialDirContext(env);
+        } catch (Exception e) {
+            // Ignore.
+        }
+
+        // Try to set this DNS resolver as primary one
+        DNSUtil.setDNSResolver(getInstance());
+    }
+    
+    private JavaxResolver() {
+        
+    }
+    
+    public static DNSResolver getInstance() {
+        if (instance == null && isSupported()) {
+            instance = new JavaxResolver();
+        }
+        return instance;
+    }
+    
+    public static boolean isSupported() {
+        return dirContext != null;
+    }
+
+    @Override
+    public List<SRVRecord> lookupSRVRecords(String name) throws NamingException {
+        List<SRVRecord> res = new ArrayList<SRVRecord>();
+
+        Attributes dnsLookup = dirContext.getAttributes(name, new String[] { "SRV" });
+        Attribute srvAttribute = dnsLookup.get("SRV");
+        @SuppressWarnings("unchecked")
+        NamingEnumeration<String> srvRecords = (NamingEnumeration<String>) srvAttribute.getAll();
+        while (srvRecords.hasMore()) {
+            String srvRecordString = srvRecords.next();
+            String[] srvRecordEntries = srvRecordString.split(" ");
+            int priority = Integer.parseInt(srvRecordEntries[srvRecordEntries.length - 4]);
+            int port = Integer.parseInt(srvRecordEntries[srvRecordEntries.length - 2]);
+            int weight = Integer.parseInt(srvRecordEntries[srvRecordEntries.length - 3]);
+            String host = srvRecordEntries[srvRecordEntries.length - 1];
+
+            SRVRecord srvRecord = new SRVRecord(host, port, priority, weight);
+            res.add(srvRecord);
+        }
+        return res;
+    }
+}