Changes to change system.

graph2/schema/root.gql

@@ -164,7 +164,7 @@ type Subscription {
   """
   Changes subscribes to the changes matching the following keys.
   """
-  changes(keys: [ChangeKeyInput!]!): Change!
+  changes(filter: ChangesFilter): Change!
 }
 
 # A Time represents a RFC3339 encoded date with up to millisecond precision.

graph2/schema/types/Change.gql

@@ -73,9 +73,12 @@ input ChangesFilter {
   "The keys to query for."
   keys: [ChangeKeyInput!]
 
+  "Only show changes by this author"
+  author: String
+
   "Only show changes more recent than this date."
   earliestDate: Time
 
-  "Limit the amount of results."
+  "Limit the amount of results. This even goes for subscriptions!"
   limit: Int
 }