Update packaging tools to support selection of preferred installer

Since 2.2 we will have both cobundle and as standalone installer (on windows only).

We expect application will have following behavior:
   * If matching JRE and JavaFX are installed then application simply starts
   * If required JavaFX need to be installed then
       * if application does not specifically request version of JRE or request JRE7 family then we offer to install appropriate cobundle
           (this should be behavior for most of existing samples created with earlier SDKs)
       * if application requests JRE6 then we offer to install (latest?) standalone JavaFX
          (and installation may fail if JavaFX installer needs JRE update)
   * If developer preference is to use standalone installer or specific version of JavaFX and they are not available on user platform then
         latest version is offered (if platform is supported)

This task is to update packaging tools to support this (ant task and javafxpackager).