Removes sep= headers, adds testing interface

Scripts/Interfaces/Testing.as

@@ -0,0 +1,13 @@
+Party@ CreateSimpleParty(const array<constString>&in species, uint8 level);
+
+Battle@ CreateSimpleBattle(uint seed, const constString&in species1, const constString&in species2, uint8 level);
+Battle@ CreateSimpleBattle(uint seed, Party@ p1, Party@ p2);
+
+// Note that this returns a ref handle, and therefore should be cast first.
+ref@ CreateMoveScript(const constString&in name);
+ExecutingMove@ CreateExecutingMove(const constString&in moveName, Pokemon@ user, Pokemon@ target);
+MoveTurnChoice@ CreateMoveTurnChoice(const constString&in moveName, Pokemon@ user, uint8 targetSide, uint8 target);
+
+bool Require(bool expression);
+bool RequireEquals(int expected, int actual);
+bool RequireEquals(const string &in expected, const string &in actual);