Make http LayoutTests work in Debian with Apache 2.4.

This patch is migrated from https://bugs.webkit.org/show_bug.cgi?id=120352
Original patch in WebKit by Allan Sandfeld Jensen <allan.jensen@digia.com>
Reviewed in WebKit by Andreas Kling.

Debian testing (jessie) and newer use Apache 2.4.

Select httpd.conf file for debian based on version, matching Fedora behavior.
Added an apache 2.4 configuration file adapted from Fedora's,
and renamed the 2.2 file to have consistent naming.

BUG=313632

Review URL: https://codereview.chromium.org/47023017

git-svn-id: svn://svn.chromium.org/blink/trunk@161058 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Make WebVTTParser::collectTimeStamp static

This function is independent of internal WebVTTParser state, while
being used outside of the actual parser.

BUG=305317

Review URL: https://codereview.chromium.org/54463002

git-svn-id: svn://svn.chromium.org/blink/trunk@161059 bbb929c8-8fbe-4397-9dbb-9b2b20218538