Allow to select several commits to modify

Currently, I cannot select several commits to stop and amend/modify:

By command line, I can select several commits and pick them for edit:

pick f7f3f6d changed my name a bit
edit 310154e updated README formatting and added blame
edit a5f4a0d added cat-file

# Rebase 710f0f8..a5f4a0d onto 710f0f8
#
# Commands:
#  p, pick = use commit
#  r, reword = use commit, but edit the commit message
#  e, edit = use commit, but stop for amending
#  s, squash = use commit, but meld into previous commit
#  f, fixup = like "squash", but discard this commit's log message
#  x, exec = run command (the rest of the line) using shell
#
# These lines can be re-ordered; they are executed from top to bottom.
#
# If you remove a line here THAT COMMIT WILL BE LOST.
#
# However, if you remove everything, the rebase will be aborted.
#
# Note that empty commits are commented out

Reference:

1. https://smartgit.userecho.com/communities/1/topics/856-allow-iterative-rebase-to-select-commits-contents-for-edition