DT plugin download java bundles from http://java.com/inc/dtoolkit.xml, and use that to collect security-baseline information.

Internally, DT store a list of security-baseline for hard-coded JRE versions, this need to change when there is a new major version of JRE, we should change that to be more flexible.

Also, we want to make sure if there is no proper bundle to download, DT and Javascript code will fall back to manual installation correctly.