generate jlink image using the moditect plugin

[chirontt]

This PR should fix issue #1

The moditect plugin execution is hooked to the package phase, so to generate the jlink image for the project, invoke the Maven package phase:

mvn package

The jlink image will be produced in target/image directory, and can be run with (e.g. in Linux/MacOS):

./target/image/bin/hellofx

or if in Windows:

target\image\bin\hellofx.bat