patchbomb: add config knob to generate flags by template (issue5354)
This can be used to flag patches by branch or topic automatically. Flags
optionally given by --flag option are exported as {flags} template keyword,
so you can add --flag V2.
#require execbit
$ hg init repo
$ cd repo
$ echo foo > foo
$ chmod 644 foo
$ hg ci -qAm '644'
$ chmod 755 foo
$ hg ci -qAm '755'
reverting to rev 0
$ hg revert -a -r 0
reverting foo
$ hg st
M foo
$ hg diff --git
diff --git a/foo b/foo
old mode 100755
new mode 100644
$ cd ..