Is there a way to allow a user to install a custom jdk on a slave machine (i.e. let the users pick a specific version from a list. Currently the jdk is hard coded into the plugin, and enforcing a specific java version would not be good (What if my slaves need have java 7 or java 8?). An example would be that java 6 u45 was the last "Open source" version of java 6, however there is a closed source version u60 which users would like to be given the option to install. Would it be possible to have a drop down to install a specific version or upload the file automatically?