unsupported threaded environment, but now they complicate code:
*) perl_clone() requires at least duplicating nginx stash;
*) the multiplicity requires to re-evalute all precompiled subroutines
   and nginx stash in new interpreter context.

    *) Change in internal API: the HTTP modules initialization was moved
       from the init module phase to the HTTP postconfiguration phase.

    *) Change: now the request body is not read beforehand for the
       ngx_http_perl_module: it's required to start the reading using the
       $r->has_request_body method.

    *) Feature: the ngx_http_perl_module supports the DECLINED return code.

    *) Feature: the ngx_http_dav_module supports the incoming "Date" header
       line for the PUT method.

    *) Feature: the "ssi" directive is available inside the "if" block.

    *) Bugfix: a segmentation fault occurred if there was an "index"
       directive with variables and the first index name was without
       variables; the bug had appeared in 0.1.29.

    *) Feature: now is possible to do several redirection using the
       "error_page" directive.

    *) Bugfix: the "dav_access" directive did not support three parameters.

    *) Bugfix: the "error_page" directive did not changes the
       "Content-Type" header line after the "X-Accel-Redirect" was used;
       the bug had appeared in 0.3.58.

    *) Feature: the "dav_access" directive.

    *) Feature: the "if" directive supports the "-d", "!-d", "-e", "!-e",
       "-x", and "!-x" operators.

    *) Bugfix: a segmentation fault occurred if a request returned a
       redirect and some sent to client header lines were logged in the
       access log.

    *) Change: now the ngx_http_charset_module works for subrequests, if
       the response has no "Content-Type" header line.

    *) Bugfix: if the "proxy_pass" directive has no URI part, then the
       "proxy_redirect default" directive add the unnecessary slash in
       start of the rewritten redirect.

    *) Bugfix: the internal redirect always transform client's HTTP method
       to GET, now the transformation is made for the "X-Accel-Redirect"
       redirects only and if the method is not HEAD; the bug had appeared
       in 0.3.42.

    *) Bugfix: the ngx_http_perl_module could not be built, if the perl was
       built with the threads support; the bug had appeared in 0.3.46.

    *) Feature: the ngx_http_perl_module supports the $r->args and
       $r->unescape methods.

    *) Feature: the method $r->query_string of ngx_http_perl_module was
       canceled.

    *) Bugfix: segmentation fault was occurred if the "none" or "blocked"
       values was specified in the "valid_referers" directive; the bug had
       appeared in 0.3.18.

    *) Feature: the ngx_http_perl_module.

    *) Change: the "valid_referers" directive allows the referreres without
       URI part.