Tutorial errors

[dialtone]

The tutorial at this URL:
http://www.twistedmatrix.com/documents/current/howto/tutorial
has some errors, and I think I found 2 of them and both on example 19.

finger19.py has a IFingerSetterFactory and a FingerSetterFactoryfromService
which don't have anything that implements IFingerSetterService (while the one
which implements it should be FingerService).

finger19a.py declares IFingerSetterService 2 times (next to each other) just at
the beginning of the file. And it leaves the "read-from-file" service
(FingerService) written while it is not used in the application
(MemoryFingerService is used instead).

Cya :)

[hypatia]

IFingerSetterService is being set up and not used in this example deliberately I
think: the next example shows the value of having the interface by setting up
MemoryFingerService which sets as well as gets values. I agree that this isn't
well explained and could do with a re-write: see issue 532.

I've made the suggested changes to finger19a.py although they won't show up on
the main website until the next Twisted release.

Marking 532 as the superseder of this issue and making you nosy. Marking this
issue done.