This shaves ~5 seconds off of a full build, not too bad. Also it just
seems nicer to push this logic out to classes. It could be better but
it's a start. :^)
Compiling anything that includes generated IPC messages is painfully
slow at the moment. This moves the encoding helpers out of line, which
helps a bit. Doing the same for decoding will help more.
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.