update deprecation warnings for v-ref & v-el

Author: yyx990803

src/deprecations.js

@@ -61,8 +61,8 @@ if (process.env.NODE_ENV !== 'production') {
 
     V_EL: function () {
       warn(
-        'v-el will no longer be a directive in 1.0.0. Use the "el" special attribute instead. ' +
-        'See https://github.com/yyx990803/vue/issues/1198 for details.'
+        'v-el will no longer be a directive in 1.0.0. Use the "$$.id" special syntax instead. ' +
+        'See https://github.com/yyx990803/vue/issues/1292 for details.'
       )
     },
 
@@ -90,9 +90,8 @@ if (process.env.NODE_ENV !== 'production') {
 
     V_REF: function () {
       warn(
-        'v-ref will no longer be a directive in 1.0.0; It will become a ' +
-        'special attribute without the prefix. Use "ref" instead.' +
-        newBindingSyntaxLink
+        'v-ref will no longer be a directive in 1.0.0; Use the "$.id" special ' +
+        'syntax instead. See https://github.com/yyx990803/vue/issues/1292 for details.'
       )
     },