Made the action bar transparent in the image view instead of hiding it.
Merge branch 'master' of https://github.com/Limvot/Mangagaga
Merge branch 'master' of https://github.com/Limvot/Mangagaga

Conflicts:
	app/src/main/java/io/githup/limvot/mangaapp/ImageViewerActivity.java
Merge branch 'master' of https://github.com/Limvot/Mangagaga
Merge branch 'master' of https://github.com/Limvot/Mangagaga
Added a settings screen with options to clear cache folder, history, or both.
Added a SettingsManager class for containing global settings during runtime.