Add file-blaming to exceptions

Methods
Public Instance methods
blame_file!(file)
     # File vendor/rails/activesupport/lib/active_support/dependencies.rb, line 205
205:   def blame_file!(file)
206:     (@blamed_files ||= []).unshift file
207:   end
blamed_files()
     # File vendor/rails/activesupport/lib/active_support/dependencies.rb, line 209
209:   def blamed_files
210:     @blamed_files ||= []
211:   end
copy_blame!(exc)
     # File vendor/rails/activesupport/lib/active_support/dependencies.rb, line 218
218:   def copy_blame!(exc)
219:     @blamed_files = exc.blamed_files.clone
220:     self
221:   end
describe_blame()
     # File vendor/rails/activesupport/lib/active_support/dependencies.rb, line 213
213:   def describe_blame
214:     return nil if blamed_files.empty?
215:     "This error occured while loading the following files:\n   #{blamed_files.join "\n   "}"
216:   end