Using character (&times;) instead of asset for publisher close button

Using a character instead of an image asset for the close button on the publisher. The character matches the screen resolution and looks better! 

__Before__
![screen shot 2014-10-10 at 8 04 45 pm](https://cloud.githubusercontent.com/assets/1065321/4601237/9875bb98-50f3-11e4-8bcd-713a3d7e4240.png)

__After__
![screen shot 2014-10-10 at 8 05 38 pm](https://cloud.githubusercontent.com/assets/1065321/4601238/988b61a0-50f3-11e4-9d8e-a3458a44e824.png)

For those of us using high resolution screens our eyes will thanks us!