Refactor: sanitizing touch on makefiles about to receive hardening

• whitespace cleanup
• internally provided -D... and -I... switches belong to CPPFLAGS rather than CFLAGS
• use a following order of the per-target flags:
  • CPPFLAGS
  • YFLAGS
  • CFLAGS
  • LDFLAGS
  • LDADD/LIBADD
  • SOURCES

This is in part to reflect common conditional inclusion of additional
sources (which should preferably immediately follow the main SOURCES
definition) sometimes connected with extending other flags as well.