Added a stern warning in a visible (in my opinion) place to make sure
    to compile with -fno-exceptions when using gcc
    Wrote a new paragraphs on OS comparison/choice in the Which OS section



Docs/manual.texi:
  Added a stern warning in a visible (in my opinion) place to make sure
  to compile with -fno-exceptions when using gcc
  Wrote a new paragraphs on OS comparison/choice in the Which OS section
BitKeeper/etc/logging_ok:
  Logging to logging@openlogging.org accepted