Handle the branch.<name>.rebase value 'interactive'

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Documentation/config.txt

@@ -684,6 +684,7 @@ branch.<name>.rebase::
 	When true, rebase the branch <name> on top of the fetched branch,
 	instead of merging the default branch from the default remote when
 	"git pull" is run.
+	When the value is `interactive`, the rebase is run in interactive mode.
 	*NOTE*: this is a possibly dangerous operation; do *not* use
 	it unless you understand the implications (see linkgit:git-rebase[1]
 	for details).

git-pull.sh

@@ -44,7 +44,15 @@ merge_args=
 curr_branch=$(git symbolic-ref -q HEAD)
 curr_branch_short="${curr_branch#refs/heads/}"
 rebase_options=
-rebase=$(git config --bool branch.$curr_branch_short.rebase)
+case "$(git config branch.$curr_branch_short.rebase)" in
+interactive)
+	rebase_options=-i
+	rebase=true
+	;;
+*)
+	rebase=$(git config --bool branch.$curr_branch_short.rebase)
+	;;
+esac
 dry_run=
 while :
 do