Loosen "working file will be lost" check in Porcelain-ish

This uses the previous update to read-tree in Porcelain-ish
commands "git checkout" and "git merge" to loosen the check
when switching branches.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

git-checkout.sh

@@ -161,7 +161,7 @@ then
     git-read-tree --reset -u $new
 else
     git-update-index --refresh >/dev/null
-    merge_error=$(git-read-tree -m -u $old $new 2>&1) || (
+    merge_error=$(git-read-tree -m -u --exclude-per-directory=.gitignore $old $new 2>&1) || (
 	case "$merge" in
 	'')
 		echo >&2 "$merge_error"
@@ -172,7 +172,8 @@ else
     	git diff-files --name-only | git update-index --remove --stdin &&
 	work=`git write-tree` &&
 	git read-tree --reset -u $new &&
-	git read-tree -m -u --aggressive $old $new $work || exit
+	git read-tree -m -u --aggressive --exclude-per-directory=.gitignore $old $new $work ||
+	exit
 
 	if result=`git write-tree 2>/dev/null`
 	then

git-merge.sh

@@ -264,7 +264,7 @@ f,*)
 	echo "Updating $(git-rev-parse --short $head)..$(git-rev-parse --short $1)"
 	git-update-index --refresh 2>/dev/null
 	new_head=$(git-rev-parse --verify "$1^0") &&
-	git-read-tree -u -v -m $head "$new_head" &&
+	git-read-tree -v -m -u --exclude-per-directory=.gitignore $head "$new_head" &&
 	finish "$new_head" "Fast forward"
 	dropsave
 	exit 0