[User story] See immediate news and then fetching new data

[programmerr47]

As a user I want to:

1. If I enter application the first time, then see progress bar. And then see list of latest news from rss sources.
2. If I reenter application or enter the second time or futher, then I need to see previously saved list of news and nice progress indicating than fetching is launched. Then I need to see updated news.

Tasks:

• Add disk cache of news
• Add different progress indicating for fetching first time and refetching news.