* dbus/Makefile.am (INCLUDES): define DBUS_COMPILATION
so we can allow ourselves to include files directly,
instead of having to use dbus.h
* dbus/dbus.h: fill in
* dbus/dbus-message.h: sketch out a sample header file.
Include griping if you include it directly instead of
* dbus/dbus-macros.h: new file with macros for extern "C",
TRUE/FALSE, NULL, etc.
* doc/file-boilerplate.c: put include guards in here