Version updates! Mostly plugins, samskivert 1.8.2.

Also added maven-dependency-plugin so that hopefully I can release without
freakoutery.

pom.xml

@@ -45,12 +45,12 @@
     <dependency>
       <groupId>com.samskivert</groupId>
       <artifactId>samskivert</artifactId>
-      <version>1.7.4</version>
+      <version>1.8.2</version>
     </dependency>
     <dependency>
       <groupId>com.google.guava</groupId>
       <artifactId>guava</artifactId>
-      <version>14.0.1</version>
+      <version>17.0</version>
     </dependency>
     <dependency>
       <groupId>net.sf.ehcache</groupId>
@@ -94,18 +94,20 @@
           <compilerArgument>-Xlint" "-Xlint:-serial" "-Xlint:-path</compilerArgument>
         </configuration>
       </plugin>
+
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-resources-plugin</artifactId>
-        <version>2.4.3</version>
+        <version>2.6</version>
         <configuration>
           <encoding>UTF-8</encoding>
         </configuration>
       </plugin>
+
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-surefire-plugin</artifactId>
-        <version>2.6</version>
+        <version>2.13</version>
         <configuration>
           <excludes>
             <exclude>com/samskivert/depot/TestCacheAdapter*.java</exclude>
@@ -114,10 +116,11 @@
           </excludes>
         </configuration>
       </plugin>
+
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-javadoc-plugin</artifactId>
-        <version>2.7</version>
+        <version>2.9.1</version>
         <configuration>
           <quiet>true</quiet>
           <show>public</show>
@@ -129,25 +132,35 @@
           </links>
         </configuration>
       </plugin>
+
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-jar-plugin</artifactId>
-        <version>2.3.1</version>
+        <version>2.5</version>
       </plugin>
+
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-install-plugin</artifactId>
-        <version>2.3.1</version>
+        <version>2.5.1</version>
       </plugin>
+
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-deploy-plugin</artifactId>
-        <version>2.5</version>
+        <version>2.7</version>
       </plugin>
+
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-dependency-plugin</artifactId>
+        <version>2.8</version>
+      </plugin>
+
       <plugin>
         <groupId>org.sonatype.plugins</groupId>
         <artifactId>nexus-staging-maven-plugin</artifactId>
-        <version>1.4.4</version>
+        <version>1.6.2</version>
         <extensions>true</extensions>
         <configuration>
           <nexusUrl>https://oss.sonatype.org/</nexusUrl>
@@ -199,7 +212,7 @@
           <plugin>
             <groupId>org.apache.maven.plugins</groupId>
             <artifactId>maven-gpg-plugin</artifactId>
-            <version>1.1</version>
+            <version>1.5</version>
             <executions>
               <execution>
                 <id>sign-artifacts</id>