Merge branch 'stable-2.15' into stable-2.16

* stable-2.15:
  Add documentation to the readonly marker file
  Upgrade bazlets to latest stable-2.14 to build with 2.14.20 API

Change-Id: I4cd19a7f35bfd86eabb9c35555a8f359af8ffebb
diff --git a/src/main/resources/Documentation/config.md b/src/main/resources/Documentation/config.md
index 2c3cb50..f8d7a1f 100644
--- a/src/main/resources/Documentation/config.md
+++ b/src/main/resources/Documentation/config.md
@@ -26,3 +26,11 @@
     Repeat with multiple values to allow more than one command or pattern
     of commands.
     The command 'gerrit plugin rm' or 'gerrit plugin remove' is always allowed.
+
+
+File gerrit.readonly
+--------------------
+
+Marker file used to enable or disable the read-only status. When present under
+the $GERRIT_SITE/etc directory, Gerrit is set to read-only and only read
+operations are enabled according to the readonly plugin configuration.
\ No newline at end of file