Catrobat/Catty — pull request #207 by rsamer (2014-05-13 23:32:19+00:00)
Title: background color issue + image cache

- moved image cache to TableViewController's-Base class to avoid duplicate code (maybe write own class that inherits from NSCache for this later, since the ImageCache-class only supports caching images from the web on disk)
- same background color for all DarkBlueGradientCells (used in all our controllers)
- disallow special characters (/\#!$%&...) for look names