SMACK-286 Made ProviderManager much more configurable.

Separated the reading of provider files from the ProviderManager.  Manager now only manages.  Added ability to add collections of providers to the manager via a ProviderLoader, of which there is one default implementation which loads from the default file format.  Now provider files can be programmatically added at any time.  Also updated the configuration abilities so that a provider file can also be set via VM arg, as well as the smack configuration itself. Introduced Java Util Logging as well.

git-svn-id: http://svn.igniterealtime.org/svn/repos/smack/branches/smack_3_4_0@13861 b35dd754-fafc-0310-a699-88a17e54d16e

source/org/jivesoftware/smack/provider/ProviderLoader.java

@@ -0,0 +1,23 @@
+package org.jivesoftware.smack.provider;
+
+import java.util.Collection;
+
+/**
+ * Used to load providers into the {@link ProviderManager}.
+ * 
+ * @author Robin Collier
+ */
+public interface ProviderLoader {
+
+    /**
+     * Provides the IQ provider info for the creation of IQ providers to be added to the <code>ProviderManager</code>.
+     * @return The IQ provider info to load.
+     */
+    Collection<IQProviderInfo> getIQProviderInfo();
+
+    /**
+     * Provides the extension providers for the creation of extension providers to be added to the <code>ProviderManager</code>.
+     * @return The extension provider info to load.
+     */
+    Collection<ExtensionProviderInfo> getExtensionProviderInfo();
+}