title: how to set the contextPath of jetty on xsbt-web-plugin?
body: <p>I'm on sbt 0.11.1 and xsbt-web-plugin 0.2.10</p>
  
  <p>here goes the build.sbt and plugins.sbt</p>
  
  <h1>build.sbt</h1>
  
  <pre><code>organization := "org"
  
  name := "demo"
  
  version := "0.1.0-SNAPSHOT"
  
  scalaVersion := "2.9.1"
  
  seq(webSettings :_*)
  
  configurationXml := 
                      &lt;configuration&gt;
                          &lt;webApp&gt;
                            &lt;contextPath&gt;/foo&lt;/contextPath&gt;
                          &lt;/webApp&gt;
                      &lt;/configuration&gt;
  
  libraryDependencies ++= Seq(
    "org.eclipse.jetty" % "jetty-webapp" % "7.4.5.v20110725" % "container",
    "javax.servlet" % "servlet-api" % "2.5" % "provided"
  )
  
  resolvers += "Sonatype OSS Snapshots" at "http://oss.sonatype.org/content/repositories/snapshots/"
  </code></pre>
  
  <h1>project/plugins.sbt</h1>
  
  <pre><code>libraryDependencies &lt;+= sbtVersion(v =&gt; "com.github.siasia" %% "xsbt-web-plugin" % (v+"-0.2.10"))
  </code></pre>
  
  <p>It seems the configurationXml doesn't work, after running container:start in sbt console, the contextPath gets the default value "/"</p>
  
  <p>how can I change the contextPath? any tips? thanks in advance! </p>