Example showing use of `JFX.pkgResourcesDir` setting to provide drop-in native packaging resources to jfx:deploy task

I've done basic testing on this on MacOS X, so an iteration or two may be required before this is finalized. However I'm interested in feedback if you have time.

I don't have a Windows machine set up at the moment to test, so before merging might want to verify that this at least builds on Windows. I did add a custom application icon for windows packages so that something is in place to determine if the default icon is getting properly overridden.

Two areas to pay particular attention to when reviewing the build definition:

1. In `project/plugin-javafx.sbt` I'm using the SBT 0.13 form of git-based plugin referencing so that the `master` version of sbt-javafx is used.  I'm not expert enough with SBT to know how to do this in a cross-version manner. Obviously should be changed once 0.6 (or whatever) is released with `JFX.pkgResourcesDir` support.
2. In `example-packaging.sbt` the setting `JFX.devKit := JFX.jdk(System.getProperty("java.home") + "/..")` was required on my machine (MacOS X 10.9.1). I've needed to have this in other projects. Not sure if this is a bug in sbt-javafx finding the default path to `ant-javafx.jar`, or some configuration issue on my computers.

Something else I noted, which I'll try to debug further: When I run the final executable on MacOS, the application name is "fxApp" and not "example-packaging". As far as I can tell, the generated `build.xml` file is correct (passing through the `name` setting properly), so it may be a bug in the version of JavaFX I'm using (a few builds behind). However, the fact that the value of `refid="fxApp"` is showing up as the application runtime name is suspicions. I'd be interested in knowing if it's correct under Windows.