new port: qt5-webkit

[RJVB (René Bertin)]

As mentioned in my submission for port:qt5-assistant, QtWebKit has recently seen a reboot/revival, and is currently at a point where it provides an interesting alternative to both the community-maintained alternative provided via Qt and its official replacement, QtWebEngine. Like port:qt5-assistant it can be built against a range of Qt versions.

See ​https://github.com/annulen/webkit/wiki for a breakdown of reasons why one might want to install/use WebKit; the main arguments that interest us are that there are still many dependents of QtWebKit, and the fact that as a dependency it is considerable less heavy.

The latter argument is esp. relevant for applications that use the library for rendering documentation: there's no need to use a full-fledged-browser-in-a-widget library for that. My proposed port takes this one step further by providing a +minimal build variant.

QtWebEngine's xz'ipped software image (5.8.0) weighs in at 33Mb (build with -Os and then stripped), QtWebKit 5.8.0 weighs a bit under 8Mb, the new QtWebKit 9Mb and the minimal 6.3Mb.

--- The port contains a number of patches that

• update the latest release (5.212.0 alpha2) with the additional commits from the stable branch
• enable building on OS X 10.9 and (hopefully) earlier
• make the build use "our" ICU libraries AND headers
• set the library compatibility version such that the resulting frameworks are a drop-in replacement for the frameworks from port:qt5-qtwebkit (or my own port:qt5-kde).

I'm in contact with the project's main developer and some of these will probably be upstreamed.

Automatic generation of the pkgconfig files doesn't work very well, so I install these from templates in ${filespath}.

Concerning the drop-in replacement nature: for this to work completely the qt5.depends_component macros will need to use path-style depspecs as far as that's not already the case. The evidently better approach would be to remove the various port:qt5*-qtwebkit ports and keep only the new port:qt5-webkit.

[RJVB (René Bertin)]

tarball of the entire port dir

[RJVB (René Bertin)]

devel/qt5-webkit/Portfile

[RJVB (René Bertin)]

Minor upgrade, including some of my upstreamed contributions.