init: disable BUG_FORLOCAL as of yash 2.49 (re: b41a9607)
init: disable BUG_FORLOCAL as of yash 2.49 (re: b41a9607)

yash 2.49 will add a new 'forlocal' shell option that can be turned
off to disable the behaviour modernish marks as BUG_FORLOCAL
without activating yash's highly restrictive POSIXly-correct mode.
Ref.: https://osdn.net/projects/yash/ticket/39372

bin/modernish (request standards compliance):
- Turn off 'forlocal' on yash if available, thus preventing the
  occurrence and detection of BUG_FORLOCAL.
- Shorten comments.

modernish/modernish