- Document NO_IGNORE, __ARCH_OK
- Make __ARCH_OK overridable, so it can be set to YES e.g. for fetching
all distfiles.
- Move ".ifndef(__ARCH_OK): block, so some targets like clean work
in any case.
- Add LOCALBASE and X11BASE to PATH in MAKE_ENV, CONFIGURE_ENV and
SCRIPT_ENV; this fixes PR 4573