tutorial still using deprecated components.Interface

[spiv]

The tutorial code still declares its interfaces as inheriting from
twisted.python.components.Interface.  This preferred way is to use
zope.interface.Interface (as described in the docstring for
twisted.python.components).

Also, this means saying "implements(IFingerService)" rather than "__implements__
= (IFingerService,)".

[I'm tempted to bump the priority of this to make it a 2.0 issue, but I'll let
others do that if they wish.]

[radix]

using my RM powers to declare this as urgent.

[hypatia]

Will try and get to this by, oh, Tuesday or so.

[hypatia]

I suck, I put it down to wanting a zope interfaces deb :)

[hypatia]

python-zopeinterface :)

[hypatia]

Making radix nosy on this one, since it is currently marked urgent.

[hypatia]

Updated the examples. Closing.