Improve -v #include search output
Re-enable full bottom-up #include search, no stopping at common parent

because this may stop the #include search too early, for example:
	foo/a.h
		#include "foo/b.h"
	foo/b.h
foo/ was seen as common parent, and then the #include stopped after trying
 	prefix/foo/foo/b.h
but it should go upwards and try
	prefix/foo/b.h
too.
Search #includes relative to their parent file, not to root file
cpp: Remove DIVIDERs if they seem to be inside statements

to avoid hick ups in the C parser.