Cooperate with InterfaceClass to ensure there is no performance penalty for this. Fixes #3

+-------------------------------------------------------------+----------------+------------------------------+------------------------------+
| Benchmark                                                   | bench_master38 | bench_issue3                 | bench_issue3_opt             |
+=============================================================+================+==============================+==============================+
| call interface (provides; deep)                             | 369 ns         | 454 ns: 1.23x slower (+23%)  | not significant              |
+-------------------------------------------------------------+----------------+------------------------------+------------------------------+
| call interface (provides; wide)                             | 373 ns         | 457 ns: 1.22x slower (+22%)  | 365 ns: 1.02x faster (-2%)   |
+-------------------------------------------------------------+----------------+------------------------------+------------------------------+
| call interface (no alternate, no conform, not provided)     | 671 ns         | 760 ns: 1.13x slower (+13%)  | 636 ns: 1.06x faster (-5%)   |
+-------------------------------------------------------------+----------------+------------------------------+------------------------------+
| call interface (alternate, no conform, not provided)        | 395 ns         | 494 ns: 1.25x slower (+25%)  | not significant              |
+-------------------------------------------------------------+----------------+------------------------------+------------------------------+
| call interface (no alternate, valid conform, not provided)  | 250 ns         | not significant              | 227 ns: 1.10x faster (-9%)   |
+-------------------------------------------------------------+----------------+------------------------------+------------------------------+
| call interface (alternate, invalid conform, not provided)   | 348 ns         | 424 ns: 1.22x slower (+22%)  | not significant              |
+-------------------------------------------------------------+----------------+------------------------------+------------------------------+

Fixes #21

The 'mostly' is because interfaces are used in cases that C3 forbids;
when there's a conflict, we fallback to the legacy algorithm. It turns
out there are few conflicts (13K out of 149K total orderings in Plone).

I hoped the fix for #8 might shake out automatically, but it didn't.

Optimize the extremely common case of a __bases__ of length one.

In the benchmark, 4/5 of the interfaces and related objects have a base of length one.

Fix the bad IROs in the bundled ABC interfaces, and implement a way to get warnings or errors.

In running plone/buildout.coredev and tracking the RO requests, the
stats for equal, not equal, and inconsistent-so-fallback, I got
{'ros': 148868, 'eq': 138461, 'ne': 10407, 'inconsistent': 12934}

Add the interface module to the Attribute str.

This was extremely helpful tracking down the Plone problem; IDate is defined in multiple modules.

The decorator specifies the component name, so it does not have to be
passed in during registration. This in turn allows developers to define
component names once globally and use it everywhere, especially when
using ZCML where the name had to be specified a second time.