Heads-up: Evolution-Data-Server and Evolution to depend on WebKit2 since 3.21.90

[Milan Crha <mcrha redhat com>]

        Hello all,
this is just a little heads-up that the evolution-data-server's
libedataserverui sub-library and the evolution itself will depend on
WebKit2 since the upcoming 3.21.90 release, unless anything really bad
would rise till the release Monday.

Big kudos to Tomas Popela, whom led this effort.

Anything what links against libedataserverui or the evolution libraries
should not use WebKit1, only WebKit2 (or no WebKit, of course), because
these two cannot be mixed in runtime. That was the reason why
the evolution-data-server wasn't ported yet, because the evolution was
still using WebKit1 and it links against libedataserverui.

The evolution-data-server dependency on WebKit is optional, it can be
avoided in the configure time by using --disable-google-auth configure
option, though it's better to have the option enabled, because it adds
some functionality for the evolution and other clients of the
evolution-data-server.
        Bye,
        Milan