rebase -i: put a nice warning into the todo list

It seems that not everybody expects a difference between keeping a "pick"
line, and deleting it.  So be a bit more explicit about that, with all
capitals to get the attention.

Noticed by vmiklos on IRC.

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-rebase--interactive.sh

@@ -401,6 +401,9 @@ do
 #  pick = use commit
 #  edit = use commit, but stop for amending
 #  squash = use commit, but meld into previous commit
+#
+# If you remove a line here THAT COMMIT WILL BE LOST.
+#
 EOF
 		git rev-list $MERGES_OPTION --pretty=oneline --abbrev-commit \
 			--abbrev=7 --reverse $UPSTREAM..$HEAD | \