title: Set font through calligraphy to all buttons in an Application
body: <p>I've seperated my UI part into a lib and am creating my styles there.</p>
  
  <p>I have a default style for all buttons and I'm setting it like this.</p>
  
  <pre><code>&lt;style name="MyTheme.Default"&gt;
       &lt;item name="buttonStyle"&gt;@style/button&lt;/item&gt;
  &lt;/style&gt;
  </code></pre>
  
  <p>My button style is</p>
  
  <pre><code>&lt;style name="button"&gt;
      &lt;item name="fontPath"&gt;fonts/myfont.ttf&lt;/item&gt;
      &lt;item name="android:gravity"&gt;center&lt;/item&gt;
      &lt;item name="android:clickable"&gt;true&lt;/item&gt;
      &lt;item name="android:textSize"&gt;14sp&lt;/item&gt;
  &lt;/style&gt;
  </code></pre>
  
  <p>I want this button style to be applied to all buttons without me calling the @style attribute. Everything seems to work fine except for the font. It's not getting applied.</p>
  
  <p>If I call using the @style attribute, it seems to apply the font.</p>
  
  <p>I can apply the font for all the texts in the application using textAppearance, this changes the font of my button as well. but this is behaviour I don't want.</p>
  
  <p>So, how can I apply a custom to buttons through my lib without explicitly using the @style attribute on every button.</p>