ACF3: Fix cannibals sometimes doing nothing for a full turn
This was because hogs got confused because walking was forbidden by SetInputMask.
Now we use a proper hedgehog effect heArtillery.
Lua scripts for engine testing. These scripts are the same as other Lua scripts
in Hedgewars, but you ought to call `EndLuaTest(TEST_SUCCESSFUL)` or
`EndLuaTest(TEST_FAILED)` when the test is completed.