[FIXED HUDSON-786] tool locations can be overridden per slave. Currently implemented for JDK, Ant, Groovy.
Plugins that want to benefit from this should implement ToolDescriptor.
See hudson.model.Ant for an example of how to do this in a backward compatible way.


git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@15737 71c3de6d-444a-0410-be80-ed276b4c234a