Removing libedataserverui

[Matthew Barnes <mbarnes redhat com>]

Starting with the upcoming release of 3.7.3, Evolution-Data-Server will
no longer include a libedataserverui.

With Evolution being the only consumer of this library nowadays, I've
decided to absorb the library back into Evolution to make improvements
to those old APIs without being restrained by backward-compatibility.

Apart from packaging changes, this should only cause minimal if any
disruption for distributors.

Matthew Barnes