Fix code style issues

Fix e-mails in JavaDoc
Fix visibility warnings in MockForwarder
Add test ensuring public methods should be public.
Simplify logic of PitImpl
Remove redundant code: unused imports, unnecessary casts
Bump gradle version
Fix code analysis issues
Disable checkstyle code analysis; TODO configure to IntelliJ-style settings and re-enable
Add new logging statements
diff --git a/src/test/java/com/intel/jndn/mock/MockFaceTest.java b/src/test/java/com/intel/jndn/mock/MockFaceTest.java
index 554f937..015da4b 100644
--- a/src/test/java/com/intel/jndn/mock/MockFaceTest.java
+++ b/src/test/java/com/intel/jndn/mock/MockFaceTest.java
@@ -168,8 +168,7 @@
   @Test
   public void testThatTransportConnectsOnPrefixRegistration() throws IOException, SecurityException {
     assertFalse(face.getTransport().getIsConnected());
-    face.registerPrefix(new Name("/fake/prefix"), (OnInterestCallback) null, (OnRegisterFailed) null,
-            (OnRegisterSuccess) null);
+    face.registerPrefix(new Name("/fake/prefix"), null, null, (OnRegisterSuccess) null);
     assertTrue(face.getTransport().getIsConnected());
   }
 
@@ -182,7 +181,7 @@
     final State state = new State();
 
     // connect callback
-    face.registerPrefix(new Name("/fake/prefix"), (OnInterestCallback) null, new OnRegisterFailed() {
+    face.registerPrefix(new Name("/fake/prefix"), null, new OnRegisterFailed() {
       @Override
       public void onRegisterFailed(final Name prefix) {
         state.regFailed = true;