LRDOCS-873 Creating UI for Service Builder Portlets

Hi Cody,

When you get a chance, can you QA the content I've added on creating the UI for Location Listing Portlet? You'll need to create an event-listing-portlet project and its two portlets with a 6.2 SDK using Liferay IDE/Studio. You'll also need to follow the tutorial from the start of the Service Builder chapter through the UI section.

- Suggestion: Instead of creating the service.xml from scratch, copy/paste the service.xml shown at the end of defining object map. 
- Important: You must use the LocationListingPortlet and LocationLocalServiceImpl from this branch, as their not updated in master yet. ;-)

Thanks!