Let Builder work again

Sorry for committing this without specs. I've not yet succeeded to run
specs... I'll try tomorrow.

lib/jenkins/plugin/proxies/builder.rb

@@ -5,6 +5,7 @@ module Jenkins
   class Plugin
     class Proxies
       class Builder < Java.hudson.tasks.Builder
+        include Java.jenkins.ruby.Get
         include Jenkins::Plugin::Proxy
 
         def prebuild(build, launcher, listener)
@@ -15,8 +16,13 @@ module Jenkins
           @object.perform(import(build), import(launcher), import(listener)) ? true : false
         end
 
+        def get(name)
+          @object.respond_to?(name) ? @object.send(name) : nil
+        end
+
       end
+
       register Jenkins::Tasks::Builder, Builder
     end
   end
-end
+end

lib/jenkins/tasks/builder.rb

@@ -4,6 +4,10 @@ module Jenkins
     ##
     # A single step in the entire build process
     class Builder
+      include Jenkins::Model
+      include Jenkins::Model::Describable
+
+      describe_as Java.hudson.tasks.Builder
 
       ##
       # Runs before the build begins
@@ -30,4 +34,4 @@ module Jenkins
       end
     end
   end
-end
+end