To add a new platform:
	1) Add target mojo to configure.in
	2) Add target mojo to arch/interface/platform.h
	3) Create a directory under arch, a la arch/bsd

NOTE:
	This is not exactly the same as adding a new backend.  When
	adding a new platform, you are adding a new backend, but a
	native one (ie, the one specified by the "native" device).  You'll
	need to make your aquisition/management funcs the following:

	void *grab_write_native(void);
		For aquiring the device (for writing) and returning a
		unique identifier

	void *grab_read_native(void);
		For aquiring the device (for reading) and returning a
		unique identifier

	ALboolean set_write_native(void *handle,
			     unsigned int *bufsiz,
			     unsigned int *fmt,
			     unsigned int *speed);
		For setting the format, rate, etc associated with
		data written to this handle.

	ALboolean set_read_native(void *handle,
			     unsigned int *bufsiz,
			     unsigned int *fmt,
			     unsigned int *speed);
		For setting the format, rate, etc associated with
		data read from this handle.

	void native_blitbuffer(void *handle, void *data, int bytes);
		Write bytes worth of data from data to the device
		specified by handle.

	void release_native(void *handle);
		close/free the audio device specified by handle.

	float get_nativechannel(void *handle, ALCenum channel);
		Return (normalized) mixer level for device specified by handle
		associated with channel.

	int set_nativechannel(void *handle, ALCenum channel, float volume);
		Set mixer level for device specified by handle
		associated with channel.

	void pause_nativedevice(void *handle);
		Inform device specified by handle about an upcoming pause.

	void resume_nativedevice(void *handle);
		Inform device specified by handle about an upcoming resume.