Add support for deleting refs

The internal API will be used by admin, and "ostree refs --delete"
is handy for interactive management.

tests/libtest.sh

@@ -44,6 +44,12 @@ assert_not_has_file () {
     fi
 }
 
+assert_not_file_has_content () {
+    if grep -q -e "$2" "$1"; then
+	echo 1>&2 "File '$1' incorrectly matches regexp '$2'"; exit 1
+    fi
+}
+
 assert_file_has_content () {
     if ! grep -q -e "$2" "$1"; then
 	echo 1>&2 "File '$1' doesn't match regexp '$2'"; exit 1

tests/t0000-basic.sh

@@ -19,7 +19,7 @@
 
 set -e
 
-echo "1..33"
+echo "1..34"
 
 . $(dirname $0)/libtest.sh
 
@@ -244,3 +244,13 @@ fi
 rm repo3 objlist-before-prune objlist-after-prune -rf
 echo "ok prune"
 
+cd ${test_tmpdir}
+$OSTREE commit -b test3 -s "Another commit" --tree=ref=test2
+ostree --repo=repo refs > reflist
+assert_file_has_content reflist '^test3$'
+ostree --repo=repo refs --delete test3
+ostree --repo=repo refs > reflist
+assert_not_file_has_content reflist '^test3$'
+echo "ok reflist --delete"
+
+