Previously flags passed by --with-ld-opt were not used when building perl
module, which meant hardening flags provided by package build systems were not
applied.

Dependancy tracking introduced in r5169 were not handled absolute path
names properly.  Absolute names might appear in CORE_DEPS if --with-openssl
or --with-pcre configure arguments are used to build OpenSSL/PCRE
libraries.

Additionally, revert part of r5169 to set NGX_INCS from Makefile
variables.  Makefile variables have $ngx_include_opt in them, which
might result in wrong include paths being used.  As a side effect,
this also restores build with --with-http_perl_module and --without-http
at the same time.

To avoid further breaks it's now done properly, all the dependencies
are now passed to Makefile.PL.  While here, fixed include list passed to
Makefile.PL to use Makefile variables rather than a list expanded during
configure.

    *) 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.

    *) Change: now nginx passes the malformed proxied backend responses.

    *) Feature: the "listen" directives support the address in the "*:port"
       form.

    *) Feature: the EVFILER_TIMER support in MacOSX 10.4.

    *) Workaround: for MacOSX 64-bit kernel kqueue millisecond timeout
       bug.
       Thanks to Andrei Nigmatulin.

    *) Bugfix: if there were several "listen" directives listening one
       various addresses inside one server, then server names like
       "*.domain.tld" worked for first address only; the bug had appeared
       in 0.3.18.

    *) Bugfix: if the HTTPS protocol was used in the "proxy_pass" directive
       and the request body was in temporarily file then the request was
       not transferred.

    *) Bugfix: perl 5.8.8 compatibility.

    *) Feature: the ngx_http_perl_module.

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