Merge branch 'sg/t-helper-gitignore'

Update the way build artifacts in t/helper/ directory are ignored.

* sg/t-helper-gitignore:
  t/helper: ignore only executable files
diff --git a/t/helper/.gitignore b/t/helper/.gitignore
index 2bad28a..48c7bb0bb 100644
--- a/t/helper/.gitignore
+++ b/t/helper/.gitignore
@@ -1,5 +1,4 @@
-*
-!*.sh
-!*.[ch]
-!*.gitignore
-
+/test-tool
+/test-fake-ssh
+/test-line-buffer
+/test-svn-fe