- eliminate ambiguities between GNU-ish and SysV-ish make flavors;
- switch [back] to -e;
- fold/unify rules;
This is follow-up to the patch introducing common BUILDENV. Idea is
to collect as much parameters in $(TOP) as possible and "strip" lower
Makefiles for most variables [and thus makes them more readable].
during "make errors" and thus during "make update".
Fix lots of bugs that util/ck_errf.pl can detect automatically.
Various others of these are still left to fix; that's why
"make update" will complain loudly when run now.
