title: Kotlin extensions unresolved references
body: <p>i stated to learn kotlin and tried to create a project by kotlin guides. In one of the guides said that i can use View's ids instead <code>findViewById</code>. I have imported <code>kotlin-android-extensions</code> plugin, added it in gradle file^ but still can't get object's reference by using only id. Can someone help me? I'm using Android Studio 2.3 and Kotlin version 1.1.2-5. Here's my code:</p>
  
  <blockquote>
    <p>Main gradle file</p>
  </blockquote>
  
  <pre><code>buildscript {
  ext.kotlin_version = "1.1.2-5"
  repositories {
      mavenCentral()
  }
  dependencies {
      classpath 'com.android.tools.build:gradle:2.3.2'
      classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
      classpath "org.jetbrains.kotlin:kotlin-android-extensions:$kotlin_version"
  
      }
  }
  </code></pre>
  
  <blockquote>
    <p>App gradle file</p>
  </blockquote>
  
  <pre><code>apply plugin: 'com.android.application'
  apply plugin: 'kotlin-android'
  apply plugin: 'kotlin-android-extensions'
  
  android {
      compileSdkVersion 25
      buildToolsVersion "25.0.0"
      defaultConfig {
          applicationId ".kotlintodoapp"
          minSdkVersion 15
          targetSdkVersion 25
          versionCode 1
          versionName "1.0"
          testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
      }
      buildTypes {
          release {
              minifyEnabled false
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
          }
      }
  }
  
  dependencies {
      compile fileTree(dir: 'libs', include: ['*.jar'])
      androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
          exclude group: 'com.android.support', module: 'support-annotations'
      })
      compile 'com.android.support:recyclerview-v7:25.2.0'
      compile 'com.android.support:appcompat-v7:25.2.0'
      compile 'com.android.support:support-v4:25.2.0'
      compile 'com.android.support:design:25.2.0'
      compile 'com.android.support.constraint:constraint-layout:1.0.2'
  
      compile 'com.pawegio.kandroid:kandroid:0.5.0@aar'
      testCompile 'junit:junit:4.12'
      compile "org.jetbrains.kotlin:kotlin-stdlib-jre7:$kotlin_version"
  }
  
  repositories {
      mavenCentral()
  }
  </code></pre>
  
  <blockquote>
    <p>activity_main.xml</p>
  </blockquote>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;RelativeLayout
      xmlns:a="http://schemas.android.com/apk/res/android"
      xmlns:tools="http://schemas.android.com/tools"
      a:id="@+id/parent_layout"
      a:layout_width="match_parent"
      a:layout_height="match_parent"&gt;
  
      &lt;android.support.v7.widget.RecyclerView
          a:id="@+id/simpleRecyclerView"
          a:layout_width="match_parent"
          a:layout_height="match_parent"/&gt;
  
  
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <blockquote>
    <p>ActivityMain.kt</p>
  </blockquote>
  
  <pre><code>import android.os.Bundle
  import android.support.v7.app.AppCompatActivity
  import kotlinx.android.synthetic.main.activity_main.*
  
  class MainActivity : AppCompatActivity() {
  
  
      override fun onCreate(savedInstanceState: Bundle?) {
          super.onCreate(savedInstanceState)
          setContentView(R.layout.activity_main)
          simpleRecyclerView.setFixedSize(true)
      }
  }
  </code></pre>
  
  <p>Android studio says that <code>kotlinx.android.synthetic.main.activity_main.*</code> is unused import, and tries to import <code>simpleRecyclerView</code> as id. </p>