Add a 'foreach' parameter to custom dashboards.

Add a 'foreach' parameter which will get appended to
all the queries in the dashboard.  This makes it easy to
have a single parameter influence all the queries which
is particularly useful if you want to vary that parameter.

Change-Id: I9e78b1410786eceba2d547914ccccdef230b130d
diff --git a/Documentation/user-dashboards.txt b/Documentation/user-dashboards.txt
index 019e978..d737815 100644
--- a/Documentation/user-dashboards.txt
+++ b/Documentation/user-dashboards.txt
@@ -43,6 +43,19 @@
 characters, as some users may find one more readable than another:
 `&` or `;` or `,`
 
+The special `foreach=...` parameter is designed to facilitate
+more easily writting similar queries in a dashboard.  The value of the
+foreach parameter will be used in every query in the dashboard by
+appending it to their ends with a space (ANDing it with the queries).
+
+Example custom dashboard using foreach to constrain a dashboard
+to changes for the current user:
+
+----
+  /#/dashboard/?title=Mine&foreach=owner:self&My+Pending=is:open&My+Merged=is:merged
+----
+
+
 Project Dashboards
 ------------------
 
@@ -78,10 +91,10 @@
 Project dashboard queries may contain the special `${project}` token
 which will be replaced with the project name to which the dashboard is
 being applied.  This is useful for defining dashboards designed to be
-inherited.  With this token, it is possible to cause a project
-dashboard to be restricted to only changes for the project in which
-an inherited dashboard is being applied by simply adding
-`project:${project}` to the queries in the dashboard.
+inherited.  With this token, it is possible to cause a query in a
+project dashboard to be restricted to only changes for the project in
+which an inherited dashboard is being applied by simply adding
+`project:${project}` to the query in the dashboard.
 
 Section dashboard
 ~~~~~~~~~~~~~~~~~