[M3C] Implement Desert Warfare

[balazskristof]

Implements Desert Warfare

It's messy.

[Susucre]

I would really appreciate some unit testing when adding such complex custom trigger.
Doesn't need to be exhaustif but some ideas of tests:

• Sacrifice a Desert
• Sacrifice a non-Desert
• Have a Desert be destroyed from the battlefield
• Discard a Desert
• Discard a non-Desert
• Mill some cards, including a few Deserts and at least one non-Desert

[balazskristof]

Tests added, checks:

• token generation
• sacrifice (both in own and opponents' turn)
• destroy
• discard (both turns)
• cycling (both turns)
• mill (both turns)
• "lands are Deserts" effects (in this case with Dune Chanter)

[JayDi85]

1. Multiple executes in one test is outdated style with many limitations and bugs. Use real time waitStack and checkXXX commands to assert your game states in single test. For custom checks you can use runCode command (you can call assertXXX inside runCode too).
2. Use setStrictMode true before each setStopAt or execute command — it will help to find missing choices (in non strict mode AI make that choices).