Using convertView for making ListView faster

Signed-off-by: Umair Khan <omerjerk@gmail.com>
Merge branch 'dev' of https://github.com/teamOSC/SubtleNews_Android_App into dev
Merge branch 'dev' of https://github.com/teamOSC/SubtleNews_Android_App into dev
Refreshing the news every 5 hours

Signed-off-by: Umair Khan <omerjerk@gmail.com>