added possibility to overwrite DefaultPluginManager (see #66)

pf4j/src/main/java/ro/fortsoft/pf4j/DefaultPluginManager.java

@@ -47,7 +47,7 @@ public class DefaultPluginManager implements PluginManager {
 	public static final String DEFAULT_PLUGINS_DIRECTORY = "plugins";
 	public static final String DEVELOPMENT_PLUGINS_DIRECTORY = "../plugins";
 
-    private File pluginsDirectory;
+    protected File pluginsDirectory;
 
     private ExtensionFinder extensionFinder;
 

pf4j/src/main/java/ro/fortsoft/pf4j/DependencyResolver.java

@@ -23,7 +23,7 @@ import ro.fortsoft.pf4j.util.DirectedGraph;
 /**
  * @author Decebal Suiu
  */
-class DependencyResolver {
+public class DependencyResolver {
 
 	private static final Logger log = LoggerFactory.getLogger(DependencyResolver.class);