[#2281] Added a TimeEntry#billable? method which is delegated to

TimeEntryActivity#billable?

lib/overhead_time_entry_patch.rb

@@ -0,0 +1,11 @@
+require_dependency 'time_entry'
+
+module OverheadTimeEntryPatch
+  def self.included(base)
+    base.class_eval do
+      unloadable
+      delegate :billable?, :to => :activity
+    end
+  end
+end
+