Added delete value method

Author: abhimanyu-bst

lib/key.js

@@ -35,6 +35,13 @@ class Key {
         this._registry.deleteKey(this);
     }
 
+    /**
+     * Deletes a value from a key
+     */
+    deleteValue (value) {
+        this._registry.deleteValue(this, value);
+    }
+
     /**
     * Sets a value for a value name on this key
     * all the containers matching the query.

lib/native/adv_api.js

@@ -66,6 +66,14 @@ var advApi = ffi.Library('Advapi32', {
       );
     */
     RegDeleteTreeA: ['long', [types.HKEY, 'string']],
+    /*
+      LONG WINAPI RegDeleteValue(
+      _In_     HKEY    hKey,
+      _In_opt_ LPCTSTR lpValueName
+      );
+    */
+
+    RegDeleteValueA: ['long', [types.HKEY, 'string']],
     /*
     LONG WINAPI RegCloseKey(
     _In_ HKEY hKey

lib/registry.js

@@ -136,6 +136,13 @@ var api = {
             throw 'Failed to open key error ' + result + ':' + error[result];
         }
     },
+    deleteValue: function (key, value) {
+        var result = advApi.RegDeleteValueA(key.handle.deref(), value);
+
+        if (result !== 0) {
+            throw 'Failed to delete value error ' + result + ':' + error[result];
+        }
+    },
     closeKey: function (key) {
         var result = advApi.RegCloseKey(key.handle.deref());