Consolidate base utility libraries into libeutil.
Evolution consists of entirely too many small utility libraries, which increases linking and loading time, places a burden on higher layers of the application (e.g. modules) which has to remember to link to all the small in-tree utility libraries, and makes it difficult to generate API documentation for these utility libraries in one Gtk-Doc module. Merge the following utility libraries under the umbrella of libeutil, and enforce a single-include policy on libeutil so we can reorganize the files as desired without disrupting its pseudo-public API. libemail-utils/libemail-utils.la libevolution-utils/libevolution-utils.la filter/libfilter.la widgets/e-timezone-dialog/libetimezonedialog.la widgets/menus/libmenus.la widgets/misc/libemiscwidgets.la widgets/table/libetable.la widgets/text/libetext.la This also merges libedataserverui from the Evolution-Data-Server module, since Evolution is its only consumer nowadays, and I'd like to make some improvements to those APIs without concern for backward-compatibility. And finally, start a Gtk-Doc module for libeutil. It's going to be a project just getting all the symbols _listed_ much less _documented_. But the skeletal structure is in place and I'm off to a good start.