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.
