Add PrefsManager
Fixes for WPM state management
Remove launcher icon attribute
Add curtain gradient asset for light theme

Allows the spritz history to appear to fade in from top properly in
both dark and light themes.
Improve SpritzFragment title / author display

Prevent ellipsizing article title, better fit text to screen.
SpritzFragment only shows article host if from url
SpritzFragment#hideActionBar
Protect against unintentional double-pause

When clicking to start the spritzer, a slight drag of the finger could
cause the spritzer to immediately stop again due to interpreting the
event as the beginning of a history drag. Now, require a history drag
to occur for at least 50ms before issuing a spritzer pause