Update iap.script_api

extension-iap/api/iap.script_api

@@ -1,6 +1,6 @@
 - name: iap
-  type: table 
+  type: table
-  desc: Functions and constants for doing in-app purchases. Supported on iOS, Android (Google Play and Amazon) 
+  desc: Functions and constants for doing in-app purchases. Supported on iOS, Android (Google Play and Amazon)
         and Facebook Canvas platforms.
         [icon:ios] [icon:googleplay] [icon:amazon] [icon:facebook]
   members:
@@ -61,6 +61,18 @@
         type: table
         desc: transaction table parameter as supplied in listener callback
 
+#*****************************************************************************************************
+
+  - name: acknowledge
+    type: function
+    desc: Acknowledge a transaction.
+        [icon:attention] Calling iap.acknowledge is required on a successful transaction on Google
+        Play unless iap.finish is called. The transaction.state field must equal iap.TRANS_STATE_PURCHASED.
+    parameters:
+      - name: transaction
+        type: table
+        desc: transaction table parameter as supplied in listener callback
+
 #*****************************************************************************************************
 
   - name: get_provider_id
@@ -203,7 +215,7 @@
 
         - name: trans_ident
           type: string
-          desc: The transaction identifier. This field is only set when `state` is 
+          desc: The transaction identifier. This field is only set when `state` is
                 `TRANS_STATE_RESTORED`, `TRANS_STATE_UNVERIFIED` or `TRANS_STATE_PURCHASED`.
 
         - name: receipt
@@ -253,47 +265,45 @@
   - name: PROVIDER_ID_AMAZON
     type: number
     desc: provider id for Amazon
-    
+
   - name: PROVIDER_ID_APPLE
     type: number
     desc: provider id for Apple
-    
+
   - name: PROVIDER_ID_FACEBOOK
     type: number
     desc: provider id for Facebook
-    
+
   - name: PROVIDER_ID_GOOGLE
     type: number
     desc: iap provider id for Google
-    
+
   - name: REASON_UNSPECIFIED
     type: number
     desc: unspecified error reason
-    
+
   - name: REASON_USER_CANCELED
     type: number
     desc: user canceled reason
-    
+
   - name: TRANS_STATE_FAILED
     type: number
     desc: transaction failed state
-    
+
   - name: TRANS_STATE_PURCHASED
     type: number
     desc: transaction purchased state
-    
+
   - name: TRANS_STATE_PURCHASING
     type: number
     desc: transaction purchasing state
           This is an intermediate mode followed by TRANS_STATE_PURCHASED. Store provider support dependent.
-    
+
   - name: TRANS_STATE_RESTORED
     type: number
     desc: transaction restored state
           This is only available on store providers supporting restoring purchases.
-    
+
   - name: TRANS_STATE_UNVERIFIED
     type: number
     desc: transaction unverified state, requires verification of purchase
-    
-