Relax response-body gating so HTML and XHTML can be buffered when
Transfer-Encoding is chunked-only, or when Content-Length is missing,
while still rejecting non-identity encodings that are not chunked HTML
and other non-HTML cases.
Update modifyHTML to cap reads for unknown length, splice the original
stream back when the cap is hit, and document the behavior in the
package README. Extend tests for themed middleware and the rewrite gate.
dd33980d18