Add .tag file to make tar balls tracable

The "git archive" operation will substitute the contents of this
file with the hash sum of the commit that this tar ball is based
on. This improves tracebility and allows to retrospectively set
tags. It has proven to be a valuable asset in mirall.

1 files changed, 1 insertions, 0 deletions

diff --git a/.tag b/.tag
new file mode 100644
index 00000000000..6828f88dcb0
--- /dev/null
+++ b/.tag
@@ -0,0 +1 @@
+$Format:%H$