Put project files within project paradigms

(1) Renamed MainActivity -> SplashActivity, renamed layouts accordingly.
(2) Renamed article -> Article
(3) Renamed article_Selection -> ArticleSelection
(4) Renamed article_Selection_Adapter -> ArticleSelectionAdapter
(5) Renamed Rss_Handler -> RssHandler
(5) Removed useless whitworthian_w.png files.
(6) Updated README