kvm tools: Tune the command-line option

With this patch we can have
	-c --cpus
	-m --mem
	-d --disk
	-k --kernel
	-i --initrd
which is more consistent and easy to remember.

The patch also frees up -s, -g option.

Ingo suggestied
'''
 The debug options should probably be concentrated under a --debug option
 anyway, to allow things like:

  --debug single-step,ioport

 Even if the debug options are kept they should be streamlined along
 the same
 pattern:

 >>         --debug-single-step     Enable single stepping
 >>         --debug-ioport          Enable ioport debugging

 But having a --debug option that recognizes all the debug flags would
 be nicer.

 It would also allow future enhancements to group debug features, like:

   --debug all                # turn on everything and the kitchen sink
   for early hangs
   --debug all,-single-step   # turn on everything except single-step
   debugging
   --debug nonverbose         # turn on all non-noisy debug options we
   have

 Maybe even:

   --debug memcheck

 ... could run kvm under valgrind automatically - that way we can hide
 any secondary tool complexities from the user and turn those tools into
 simple debug options :-)
'''

Let's do this --debug option consolidation later.

Signed-off-by: Asias He <asias.hejun@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>