LPS-42356 Save/Cancel buttons are cutoff when large/long logo is uploaded on Portal Settings page

Jira ticket: https://issues.liferay.com/browse/LPS-42356

* Not a problem in Chrome or IE 8-11
   * The width for images is set to 'auto' in relation to the parent and there is a max-width property set to 100%
* In Firefox however, these rules it don't set the width of the image to 100% the width of the container (which is expected), but rather the full natural width of the image. 
   * The problem is a larger issue of how firefox sizes fieldset elements -- they are allowed to resize based on their child elements instead of the other way around
* There were two issues:
   * The image could overflow its column and overlap the right sidebar
   * The entire page could expand if the image was too large
* For each issue, there was a corresponding fieldset that was expanding to be larger than its container based on the size of its children
   * By specifying a display property for each of the fieldsets, this behavior no longer occurs