Add new design for modal slideshow view

Modal slideshow view updated with new design (sul-dlss/spotlight#554)- 

* Replaced bootstrap-carousel extension with custom functions 
* Changed modal to full-screen with centered image
* Removed indicators and play/pause related controls

![modal-slideshow](https://f.cloud.github.com/assets/302258/2484371/960f1502-b10c-11e3-9c82-86b60733c365.png)

To-do: On image hover, move caption as a slide-in with configurable text truncation