title: Define java option in with sbt-native-packager
body: <p>I have this build.sbt file :</p>
  
  <pre><code>import NativePackagerHelper._
  import NativePackagerKeys._
  
  packageArchetype.java_application
  
  name := """IdTabDriver"""
  version := "1.0.0.1"
  
  name in Windows := "IdTabDriver"
  
  packageSummary in Windows := "IdTabDriver"
  
  packageDescription in Windows := "IdTabDriver"
  
  maintainer in Windows := "Access France"
  
  organization := "Access France"
  
  lazy val root = (project in file(".")).enablePlugins(PlayJava)
  
  scalaVersion := "2.10.4"
  
  mappings in Universal ++= directory("keys")
  
  batScriptExtraDefines in Windows += """set _JAVA_OPTS=%_JAVA_OPTS% -Dconfig.file=%IDTABDRIVER_HOME%\\conf\\application.conf"""
  
  libraryDependencies ++= Seq(
    cache,
    javaWs,
    "commons-configuration" % "commons-configuration" % "1.10",
    "org.rxtx" % "rxtxcomm" % "2.0-7pre1"
  )
  </code></pre>
  
  <p>I want to set some parameters (define from now in application.conf) but the <code>batScriptExtraDefines</code> seems to be ignored... It is parsed by my IDE as conform symbol but it doesn't affect the generated .bat ...</p>
  
  <p>I have also tried to add </p>
  
  <pre><code>javaOptions in Universal ++= Seq(
    //app parameters
    "-Dhttps.port=44360",
    "-Dhttps.keyStore=keys/server.p12",
    "-Dhttps.keyStoreType=pkcs12",
    "-Dhttps.keyStorePassword=12345678"
  )
  </code></pre>
  
  <p>But it doesn't make anything.</p>
  
  <p>What have I missunderstood ?</p>
  
  <p>PS: I'm using sbt-native-packager 0.8.0</p>