implemented dynamically setting newsstand icon when loading baker manifest (shelf.json)
Merge pull request #351 from tobiasstrebitzer/feature-dynamic-newsstand-icon

Feature: Dynamic Newsstand Icon
Fixes #303
Merge branch 'master' of https://github.com/bakerframework/baker
Converted the master branch to ARC.
Converted master to modern Objective-C syntax.
Merge branch 'refs/heads/arc'
First step in the many steps of doing a complete code review and cleanup.
implemented category selection by setting 'categories' array in json manifest file