To make Evolution's shared libraries more consistent.

Also rename the documentation module to evolution-util.

Basically any place where we use both EClient and ESourceComboBox.

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.

One last time.

To be used in the Account Editor to list authentication mechanisms.

We have a confusing array of nearly-identical CFLAGS/LIBS definitions in
configure.ac.  Time to simplify.  Instead let's just have one definition
that includes all the libraries provided by Evolution-Data-Server (incl.
Camel).  That, in combination with GNOME_PLATFORM, gives us most of what
we need for compliation and linking, and we can sprinkle definitions for
additional library dependencies in Makefile.am's as needed.

We now have a proper junk mail filtering API.  All junk filtering
extensions must subclass EMailJunkFilter for user preferences and
availability testing, and implement the CamelJunkFilter interface
for the actual junk filtering and learning operations.

The bogofilter module should be feature-equivalent to its former
EPlugin.  The spamassassin module is far more complex.  It's nearly
feature-equivalent to its former EPlugin, but I ditched the spamd
respawning code since it seemed unnecessary for a mail client to
have to deal with.  If there's a huge outcry from users about it
I'll reluctantly put it back, but I don't expect one.

This gets us a step closer to killing off EConfig, and eventually
the EPlugin framework itself.