Add SPARK_CLOUD=n to the make cmd line to compile-time exclude the cloud.

(Requires a clean build of wiring.)

Mostly #ifdef/#endif, with some formatting changes.

Before:
 text	   data	    bss	    dec	    hex	filename
  80220	   1144	  11580	  92944	  16b10	../build/target/main/prod-0/main.elf
After:
   text	   data	    bss	    dec	    hex	filename
  45228	   1124	   8596	  54948	   d6a4	../build/target/main/prod-0/main.elf

So ca 3k ram and 35k flash saved.