Merge from vendor branch TNF:

Merge from vendor branch TNF:
Import webkit-gtk3-1.4.2 as www/webkit-gtk3.

WebKit is an open source web browser engine. WebKit is also the name of
the Mac OS X system framework version of the engine that's used by
Safari, Dashboard, Mail, and many other OS X applications. WebKit's HTML
and JavaScript code began as a branch of the KHTML and KJS libraries
from KDE.

This is the GTK3+ port of the engine.