title: Could not find property on project
body: <p>I'm trying to use the Grgit plugin, and I want to reference <code>Grgit</code> from a separate <code>gradle</code> file. </p>
  
  <p>Gradle is able to find <code>Grgit</code> when I try it like this:</p>
  
  <p><strong><em>./build.gradle:</em></strong></p>
  
  <pre><code>buildscript {
      repositories {
          mavenCentral()
      }
  
      dependencies {
          classpath 'com.android.tools.build:gradle:0.10.+'
          classpath 'org.ajoberstar:gradle-git:0.8.+'
      }
  }
  
  import org.ajoberstar.grgit.*
  
  def repo = Grgit.open(".")
  </code></pre>
  
  <p>However, when I move the two last lines to a separate <code>file.gradle</code>, like below, it doesn't work:</p>
  
  <p><strong><em>./build.gradle:</em></strong></p>
  
  <pre><code>buildscript {
      repositories {
          mavenCentral()
      }
  
      dependencies {
          classpath 'com.android.tools.build:gradle:0.10.+'
          classpath 'org.ajoberstar:gradle-git:0.8.+'
      }
  }
  
  apply from: 'file.gradle'
  </code></pre>
  
  <p><strong><em>./file.gradle:</em></strong></p>
  
  <pre><code>import org.ajoberstar.grgit.*
  
  def repo = Grgit.open(".")
  </code></pre>
  
  <hr>
  
  <p>The error shown:</p>
  
  <pre><code>Could not find property 'Grgit' on root project 'MyProject'.
  </code></pre>
  
  <p>How can I use <code>Grgit</code> in a separate file?</p>