Allow everything to be built from the top level directory with just
'make', cleaned with 'make clean', and installed with 'make
install'. Also support these in any particular subdirectory.
Specifying 'make VERBOSE=1' will print each ld/g++/etc. command as
it runs.
Kernel and early host tools (IPCCompiler, etc.) are built as
object.host.o so that they don't conflict with other things built
with the cross-compiler.
This patch introduces the second MenuApplet: Audio. To make this work,
menu applet windows now also receive mouse events.
There's still some problem with mute/unmute via clicking not actually
working, but the call goes from the applet program over IPC to the
AudioServer, where something goes wrong with the state change message.
Need to look at that separately.
Anyways, it's pretty cool to have more applets running in their own
separate processes. :^)
