https://bugs.webkit.org/show_bug.cgi?id=98602

Reviewed by Eric Seidel.

Tools: 

Unify all the different `Listen' directives present in the several
httpd.conf files we have in LayoutTests/http/conf. For one, we
were already passing `Listen 127.0.0.1:8000' via webkitpy before,
and opening the other ports from the conf files.

The configuration files differed mostly in the way they handled
IPV6 ports. Some of them did not listen to IPV6 ports because the
systems which used them sometimes did not have IPV6 support. The
`http_server_supports_ipv6' method has been added to Port to
address that. cygwin, on its turn, still seems to use Apache 1.3,
which does not support IPV6 at all; the newly-added method has a
special case for that.

* Scripts/webkitpy/common/system/platforminfo_mock.py:
(MockPlatformInfo.is_cygwin):
* Scripts/webkitpy/layout_tests/port/base.py:
(Port.baseline_version_dir):
(Port.to.start_websocket_server):
(Port.to):
(Port.to.http_server_supports_ipv6):
* Scripts/webkitpy/layout_tests/port/base_unittest.py:
(PortTest.test_http_server_supports_ipv6):
(PortTest.test_build_path):
* Scripts/webkitpy/layout_tests/servers/apache_http_server.py:
(LayoutTestApacheHttpd):
(LayoutTestApacheHttpd.__init__):

LayoutTests: 

* http/conf/apache2-debian-httpd.conf: Remove the `Listen'
directive and related comments, it is passed to httpd by webkitpy
now.
* http/conf/apache2-httpd.conf: Ditto.
* http/conf/cygwin-httpd.conf: Ditto.
* http/conf/fedora-httpd.conf: Ditto.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@130596 268f45cc-cd09-0410-ab3c-d52691b4dbfc