LU-883 commit: commit-msg rewrite

LU-883 commit: commit-msg rewrite

 1. do global initializations in function.
    collect the read only and state monitoring initializations
    to one place where they can be easily identified.

 2. Move the signoff and changeid code to functions.
    Have them call a "ck_wrapup" function to validate
    the processing state for doing the summary/changeid/etc.
    change-id: may now appear before signed-off-by:

 3. Move the wrap up validations to the first-time-through-wrapup
    code in ck_wrapup.

 4. add a function for handling innocuous tag lines.
    Only call "ck_wrapup".

 5. Remove all $LINE echoing to the end of the case statement.
    Use "break" and/or "continue" to bypass line echo.

 6. use [ ${#foo} -gt 0 ] in preference to [ $foo ].
    This scriptlett will echo "no":
      $ f='! -z' ; [ $f ] && echo yes || echo no
    You could quote "$f", but directly checking length more
    correctly represents the intent.

 7. Removed conditions for setting HAS_LAST_BLANK=true because
    the conditions were written to be *ALWAYS* true.
      foo=false
      [ $foo ] && echo hi there
    will always echo out, "hi there".

 8. eliminate the convoluted and slightly wrong state management
    for trying to identify a "diff" block.  Instead, just read
    in the next line in that case clause and either break out
    of the read loop or echo out both of the lines.

 9. Do not fork and exec a bunch of programs when ${#LINE} will
    directly tell you how many characters are in the line.

10. do default line processing in a function, too.  Makes regex
    code selection much easier to understand.  Also allowed
    me to remove the ";&" case statement fall-through construct.
    Removed $HAS_SIGNOFF check since $IS_WRAPPING_UP is tested
    upon function entry.

11. emacs editor hints.

12. TODO: read the first two lines outside of the loop and
    verify that they are up to snuff.  Then remove a bunch of
    checks scattered about the code.  Line counting, etc., etc.

Signed-off-by: Bruce Korb <bruce_korb@xyratex.com>
Change-Id: I30a4a9b77b82af9f9b965823487001cbd5c28230
Reviewed-on: http://review.whamcloud.com/1764
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>