Add all=1 query param for atom feeds

Displays all items from all branches in one feed

Signed-off-by: Aaron Griffin <agriffin@datalogics.com>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>
diff --git a/ui-atom.c b/ui-atom.c
index 808b2d0..9f049ae 100644
--- a/ui-atom.c
+++ b/ui-atom.c
@@ -85,7 +85,9 @@
 	struct rev_info rev;
 	int argc = 2;
 
-	if (!tip)
+	if (ctx.qry.show_all)
+		argv[1] = "--all";
+	else if (!tip)
 		argv[1] = ctx.qry.head;
 
 	if (path) {