Added css to set height and scroll content

Modal scrolls its body content and will fit in the iframe under the
“Themed Bootstrap Controls” section found here:
http://exacttarget.github.io/fuelux/mctheme/index.html#mctheme
no more scrolling

Refactored to remove scrolling modal body and removed content from
modal to reduce its height.
Merge pull request #39 from ExactTarget/Issue-25--Modal-example

Added css to set height and scroll content