Minor changes to wording in theorems 1 and 3

Changes the phrasing slightly, but should not change the content or meaning
of any statements in the paper.
Remove weak-stationarity requirement in theorem 1

Under the null, the mean is zero; so assuming covariance stationarity is
just a restriction on the variances.  That restriction isn't necessary for
the CLT to hold, so I'm removing it.
Add requirement of constant mean to theorem 3

Without a constant mean, the OOS bootstrap used in Theorem 3 is not valid.
So I'm adding the assumption.
Removed separate reference to tech. appendix

Since I'm not using literate programming anymore, citing the software you
used in the paper seems tacky.  I'm taking it out.
Edit Lemma A.1

Tweaks proof and adds additional conditions.
in-process changes to lemma A2