backout: avoid redundant message examination
Before this patch, "hg backout" examines "--message" and "--logfile"
options explicitly.
But this examination is redundant, because "commitfunc()" can receive
the result of same examination by "cmdutil.logmessage()" in
"cmdutil.commit()" through "message" argument.
This patch avoids redundant message examination by "message"
examination in "commitfunc()".
Ancestors of 5
4 2 0
Ancestors of 6 and 5
3 4 2 1 0
Ancestors of 5 and 4
4 2 0
Ancestors of 7, stop at 6
6
Ancestors of 7, including revs
7 6 5 3 4 2 1 0
Ancestors of 7, 5 and 3, including revs
7 5 3 6 4 2 1 0
Descendants of 5
7 8
Descendants of 5 and 3
6 7 8
Descendants of 5 and 4
5 7 8