Add Legendary: Villains cards to the interface.

Sticking with all of the base set Legendary terms for now.

[GH-15]
Add cucumber tests for Villains.

No change in expectation made on examples using Uncanny Avengers; need
to add a special "notes" column to deal with Wolverine's Overrun
ability--this will be much easier to do than actually calculating how
many times he can possibly Overrun.

Use Avengers only with the Plot "Crown Thor King of Asgard" because when
they are together is the only time either of them really affects the
speed of the Villain/Adversary Deck.

[GH-15]
Implement Plot Graduation at Xavier's X-Academy

While *technically* this Plot doesn't have a "Good Wins" condition on
Twist 8, if no Bystanders are carried to safety there will still be 8 in
the overrun pile on Twist 8 as each Twist puts one there.

Fixes 3 tests.

[GH-15]
Implement Plot: Resurrect Heroes with Norn Stones

There are 6 cards that require playing one more from the
Adversary/Villain Deck; need to watch out for this if there's ever a way
to play with 3 Twists fewer than normal.

Fixes 3 tests.

[GH-15]
Implement Commander: Dr. Strange

[GH-15]
Implement Commander: Professor X

At the moment, this is incorrectly implemented; Professor X can play up
to 3 cards regardless of the Villain/Adversary groups being used. It
should only work when there are at least 3 cards in that Deck with
"X-Treme Attack," which at this time means when any of Uncanny Avengers,
Uncanny X-Men, or X-Men First Class are being used.

In all 3+ player games, and 2 player games not using the Kree-Skrull
War, Professor X will lead X-Men First Class. The Solo Mode rules added
in the "Commander Abilities Linked to Specific Adversary Groups" section
of the Legendary: Villains rulebook do not give the Group being used
"X-Treme Attack".

The current cucumber tests assume the correct implementation; this
change makes some tests fail, and others pass, for a net change of 0
tests with different results.

[GH-15]
Fix Professor X implementation.

This method will need further refactoring should a new Adversary group
come out featuring 2 or fewer cards with "X-Treme Attack". This will
also need to be changed if some edge case can be found involving
henchmen (like Mole Man's problem in GH-3).

[GH-15]
Implement Plot: Crown Thor King of Asgard

[GH-15]
Implement special notes for Uncanny Avengers

Figuring out exactly how many times Wolverine can overrun sounds
hard. For now, any subclass of VillainDeckSet can define a string (or an
array of strings) to display after "Additional Notes" in the
interface (note that right now, only notes from Villain/Adversary groups
are included in the response in SubmissionHandler).

Always leave a note.

[GH-15]
Implement Plot: Mass Produce War Machine Armor

This plot has unusual setup for 1 player; the Henchmen/Backup Adversary
group is set, and is always 10 copies instead of 3--like the setup for
Organized Crime Wave.

[GH-15]
Add tests for setups for all Plots.

Need to add special case for Crown Thor King of Asgard with Avengers as
the Adversary group; the villain_count for that setup should be 1 less
as Thor is set next to the Plot instead of in the Villain/Adversary
Deck.

[Closes GH-15]
[Closes GH-17]
Merge pull request #19 from michaeljb/implement-villains

Implement cards from Villains