* configure.in: pile on more warning flags if using gcc

	* Doxyfile.in (EXTRACT_STATIC): set to NO, so we don't have
	to document static functions

	* configure.in: add summary to end of configure so it
	looks nice and attractive

	* dbus/dbus-hash.c: finish implementation and write unit
	tests and docs

	* configure.in: add --enable-tests to enable unit tests

	* dbus/dbus-test.c: test program to run unit tests
	for all files in dbus/*, initially runs a test for
	dbus-hash.c

	* dbus/dbus-internals.h: file to hold some internal utility stuff