IconicsImageView is not displaying icons when added in XML
Hi,
thanks for this very useful library!

I'm having an issue with IconicsImageView. When I use it in XML, icon and color is not displayed in the app.

My XML:

``` xml
<com.mikepenz.iconics.view.IconicsImageView
    android:id="@+id/icon"
    android:layout_width="20dp"
    android:layout_height="20dp"
    app:iiv_color="@android:color/white"
    app:iiv_icon="faw-plus"
    android:layout_marginRight="10dp"/>
```

However when I add icon to this view by code it works:

``` java
@Bind(R.id.icon) IconicsImageView mIcon;
mIcon.setIcon("faw-plus");
```

Other views IconicsTextView and IconicsButton work without any problems.

My gradle file:

``` json
compileSdkVersion 22
buildToolsVersion "22.0.1"
minSdkVersion 15
targetSdkVersion 22

compile 'com.mikepenz:iconics-core:1.7.4@aar'
```
