Updated to plexus-archiver 2.6.1, plexus-io 2.1.1 and plexus-utils 3.0.18

Full symlink support on *NIX (java7+ required), full file attribute support (java7+ required)

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1628095 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/pom.xml b/pom.xml
index 6fe6fee..1e6b8a5 100644
--- a/pom.xml
+++ b/pom.xml
@@ -123,7 +123,7 @@
     <dependency>
       <groupId>org.codehaus.plexus</groupId>
       <artifactId>plexus-archiver</artifactId>
-      <version>2.5</version>
+      <version>2.6.1</version>
     </dependency>
     <dependency>
       <groupId>org.codehaus.plexus</groupId>
@@ -144,7 +144,7 @@
     <dependency>
       <groupId>org.codehaus.plexus</groupId>
       <artifactId>plexus-utils</artifactId>
-      <version>3.0.15</version>
+      <version>3.0.18</version>
     </dependency>
     <dependency>
       <groupId>org.apache.maven.shared</groupId>