Add link support to PDF viewer including option to highlight

Provide Objective C source code for XCode necessary to add link support to a pdf viewer based on CGPDFDocument. A sample project can be found at: [login to view URL] . The iPad user should be able to tap on links in the document to navigate to other pages in the document as well as other pdf documents. The user should be able to turn on highlighting of links as an option. Links to non pdf documents should raise events in the application which can be handled by the code to open other viewers to be developed. For the purposes of this project a link to a video could simply display a dialog saying "File: [file path] could not be displayed". We will have many additional projects this is just an initial a proof of concept.