Spring fixes

Remember how a while back I fixed things like being stuck under a spring after jumping from below? Or how you could touch multiple springs at the same time and subsequently cause a loud racket? I accidentally broke something else in the process it turns out! (this sounds familiar...)

Namely, diagonal springs can't send you to their centers anymore, because of several changes I made to player-spring collision towards the other issues. This branch fixes that particular issue, while making sure none of the old bugs were broken again. Took a lot of testing to make sure of this.

As a bonus, the P_DoSpring function returns a boolean now, which can be used by Lua for whatever: true = you touched spring; false = you didn't

src/lua_baselib.c

@@ -1009,8 +1009,8 @@ static int lib_pDoSpring(lua_State *L)
NOHUD
if (!spring || !object)
return LUA_ErrInvalid(L, "mobj_t");
-	P_DoSpring(spring, object);
-	return 0;
+	lua_pushboolean(L, P_DoSpring(spring, object));
+	return 1;
}
// P_INTER