Enable checkstyle Javadoc Comment Style rule

Turn on the Javadoc Comment Style rule and fix
any violations that come up.  This is related to
requiring javadoc description comments to end
with a '.'

Change-Id: I19cf1b9f00d3040987e0b4c8b39461e2e0ad66b5
diff --git a/src/main/java/net/onrc/onos/core/packet/BPDU.java b/src/main/java/net/onrc/onos/core/packet/BPDU.java
index 583eeff..ce0d9a2 100644
--- a/src/main/java/net/onrc/onos/core/packet/BPDU.java
+++ b/src/main/java/net/onrc/onos/core/packet/BPDU.java
@@ -21,7 +21,7 @@
 
 /**
  * This class is a Rapid Spanning Tree Protocol
- * Bridge Protocol Data Unit
+ * Bridge Protocol Data Unit.
  *
  * @author alexreimers
  */
diff --git a/src/main/java/net/onrc/onos/core/packet/DHCP.java b/src/main/java/net/onrc/onos/core/packet/DHCP.java
index aea1ab1..e2a109e 100644
--- a/src/main/java/net/onrc/onos/core/packet/DHCP.java
+++ b/src/main/java/net/onrc/onos/core/packet/DHCP.java
@@ -51,6 +51,7 @@
      * ------------------------------------------
      * |            options (312)               |
      * ------------------------------------------
+     * Basic packet.
      */
     // Header + magic without options
     public static final int MIN_HEADER_LENGTH = 240;
@@ -279,7 +280,7 @@
     }
 
     /**
-     * Gets a specific DHCP option parameter
+     * Gets a specific DHCP option parameter.
      *
      * @param opetionCode The option code to get
      * @return The value of the option if it exists, null otherwise
diff --git a/src/main/java/net/onrc/onos/core/packet/Ethernet.java b/src/main/java/net/onrc/onos/core/packet/Ethernet.java
index 19e7c70..ef088db 100644
--- a/src/main/java/net/onrc/onos/core/packet/Ethernet.java
+++ b/src/main/java/net/onrc/onos/core/packet/Ethernet.java
@@ -57,7 +57,7 @@
     protected boolean pad = false;
 
     /**
-     * By default, set Ethernet to untagged
+     * By default, set Ethernet to untagged.
      */
     public Ethernet() {
         super();
@@ -323,7 +323,7 @@
     }
 
     /**
-     * Convert a long MAC address to a byte array
+     * Convert a long MAC address to a byte array.
      *
      * @param macAddress
      * @return the bytes of the mac address
@@ -478,7 +478,7 @@
         } else if (pkt instanceof BPDU) {
             sb.append("\nbpdu packet");
         } else {
-            sb.append("\nunknwon packet");
+            sb.append("\nunknown packet");
         }
 
         return sb.toString();
diff --git a/src/main/java/net/onrc/onos/core/packet/ICMP.java b/src/main/java/net/onrc/onos/core/packet/ICMP.java
index eb42f96..c1a0883 100644
--- a/src/main/java/net/onrc/onos/core/packet/ICMP.java
+++ b/src/main/java/net/onrc/onos/core/packet/ICMP.java
@@ -20,7 +20,7 @@
 import java.nio.ByteBuffer;
 
 /**
- * Implements ICMP packet format
+ * Implements ICMP packet format.
  *
  * @author shudong.zhou@bigswitch.com
  */
diff --git a/src/main/java/net/onrc/onos/core/packet/IPacket.java b/src/main/java/net/onrc/onos/core/packet/IPacket.java
index 8f31960..9cbba4d 100644
--- a/src/main/java/net/onrc/onos/core/packet/IPacket.java
+++ b/src/main/java/net/onrc/onos/core/packet/IPacket.java
@@ -18,7 +18,7 @@
 package net.onrc.onos.core.packet;
 
 /**
- * @author David Erickson (daviderickson@cs.stanford.edu)
+ * @author David Erickson (daviderickson@cs.stanford.edu).
  */
 public interface IPacket {
     /**
@@ -44,20 +44,20 @@
     public IPacket setParent(IPacket packet);
 
     /**
-     * Reset any checksums as needed, and call resetChecksum on all parents
+     * Reset any checksums as needed, and call resetChecksum on all parents.
      */
     public void resetChecksum();
 
     /**
      * Sets all payloads parent packet if applicable, then serializes this
-     * packet and all payloads
+     * packet and all payloads.
      *
      * @return a byte[] containing this packet and payloads
      */
     public byte[] serialize();
 
     /**
-     * Deserializes this packet layer and all possible payloads
+     * Deserializes this packet layer and all possible payloads.
      *
      * @param data
      * @param offset offset to start deserializing from
diff --git a/src/main/java/net/onrc/onos/core/packet/IPv4.java b/src/main/java/net/onrc/onos/core/packet/IPv4.java
index 8933203..72efa61 100644
--- a/src/main/java/net/onrc/onos/core/packet/IPv4.java
+++ b/src/main/java/net/onrc/onos/core/packet/IPv4.java
@@ -431,7 +431,7 @@
 
     /**
      * Accepts an IPv4 address and returns of string of the form xxx.xxx.xxx.xxx
-     * ie 192.168.0.1
+     * ie 192.168.0.1.
      *
      * @param ipAddress
      * @return