options to use a JRE packaged within application

I've package a minimal java app `System.out.println(System.getProperty("java.version"));` and included openjdk 1.7.0_40 JRE in ZIP.

     java.version=custom
     java.home=$app_dir/app/jdk1.7.0_40

app output :

    1.7.0_40-ea

### benefits
* let customer choose JRE version without engineering extra effort
* reasonable workaround for JCE unlimited strength issue

### drawbacks
* application ZIP grows by 50Mb
* customer can use arbitrary binary as JRE