title: Error when to compile my theme with vaadin 7.3 and valo theme
body: <p>I'm developing a vaadin application which used vaadin v7.2. Now it is updated to v7.3.7 and used the new valo theme with my custom styles. When compiling the whole project using <code>mvn clean install</code> the theme getting compile perfectly. But when I try to compile the theme using command prompt with below command</p>
  
  <pre><code>java -cp '../../../../../../target/product-webapp-1.1.3.0-SNAPSHOT/WEB-INF/lib/*' com.vaadin.sass.SassCompiler styles.scss styles.css
  </code></pre>
  
  <p>it pushes a valo not found error like below</p>
  
  <pre><code>java.io.FileNotFoundException: Import '../valo/valo.scss' in '/home/lahirub/Documents/PROJECTS/NewClearProduct/newclear-product-webapp/src/main/webapp/VAADIN/themes/mytheme/styles.scss' could not be found
  
  com.vaadin.sass.internal.parser.ParseException: Mixin Definition: valo not found
  </code></pre>
  
  <p>My custom theme is like this</p>
  
  <p>mytheme.scss</p>
  
  <pre><code>@import "../valo/valo.scss";
  
  @mixin mytheme {
    @include valo;
  
    // Insert your own theme rules here
  }
  </code></pre>
  
  <p>styles.scss</p>
  
  <pre><code>@import "mytheme.scss";
  @import "addons.scss";
  
  // This file prefixes all rules with the theme name to avoid causing conflicts with other themes.
  // The actual styles should be defined in mytheme.scss
  
  .mytheme {
    @include addons;
    @include mytheme;
  
  }
  </code></pre>
  
  <p>addons.scss</p>
  
  <pre><code>/* Import and include this mixin into your project theme to include the addon themes */
  @mixin addons {
  }
  </code></pre>
  
  <p>I'm unable to find the reason for this error. Can anyone please give me some suggestion.</p>