Add initializer tests and move classpath files

The initializer tests verify that every non-optional initializer, this
includes Providers, is loadable.

Creating files under META-INF is not considered best practice. Smack's
configuration and provider files reside now in classpath directory
qualified by Smack's package namespace.

core/src/main/resources/org.jivesoftware.smack/core.providers

@@ -0,0 +1,12 @@
+<?xml version="1.0"?> 
+<!-- Providers file for default Smack extensions -->
+<smackProviders> 
+
+    <!-- Privacy -->
+    <iqProvider>
+        <elementName>query</elementName>
+        <namespace>jabber:iq:privacy</namespace>
+        <className>org.jivesoftware.smack.provider.PrivacyProvider</className>
+    </iqProvider>
+
+</smackProviders>

core/src/main/resources/org.jivesoftware.smack/jul.properties

@@ -0,0 +1,3 @@
+# Java Util Logging configuration for Smack.
+handlers = java.util.logging.ConsoleHandler
+.level = WARNING

core/src/main/resources/org.jivesoftware.smack/smack-config.xml

@@ -0,0 +1,35 @@
+<?xml version="1.0"?>
+<!-- Smack configuration file. -->
+<smack>
+
+    <!-- Packet reply timeout in milliseconds -->
+    <packetReplyTimeout>5000</packetReplyTimeout>
+
+    <!-- Enable/Disable local Socks5 proxy -->
+    <localSocks5ProxyEnabled>true</localSocks5ProxyEnabled>
+
+    <!-- Port of the local Socks5 proxy -->
+    <localSocks5ProxyPort>7777</localSocks5ProxyPort>
+
+    <!-- Port of the local Socks5 proxy -->
+    <packetCollectorSize>10000</packetCollectorSize>
+    
+    <!-- Automatic enable Entity Caps (XEP-0115) for new connections -->
+    <autoEnableEntityCaps>false</autoEnableEntityCaps>
+    
+    <!-- Classes that will be loaded when Smack starts -->
+    <startupClasses>
+        <className>org.jivesoftware.smack.initializer.CoreInitializer</className>
+        <className>org.jivesoftware.smack.initializer.VmArgInitializer</className>
+        <className>org.jivesoftware.smack.PrivacyListManager</className>
+        <className>org.jivesoftware.smack.ReconnectionManager</className>
+    </startupClasses>
+
+    <optionalStartupClasses>
+        <className>org.jivesoftware.smack.util.dns.JavaxResolver</className>
+        <className>org.jivesoftware.smackx.ExtensionsProviderInitializer</className>
+        <className>org.jivesoftware.smackx.ExtensionsStartupClasses</className>
+        <className>org.jivesoftware.smackx.ExperimentalProviderInitializer</className>
+        <className>org.jivesoftware.smackx.WorkgroupProviderInitializer</className>
+    </optionalStartupClasses>
+</smack>