More traditional list item style for dreams settings.

Other improvements:
 - remove "Start dreaming now", promote "When to dream" to action bar
 - added logging
 - hide dream settings button if n/a
 - new flat style for settings/preview + dividers
 - refresh dreams list when packages are installed/uninstalled
 - added placeholder for help url

Bug:7010260
Change-Id: Ia443b4f76678eaf1a52b907d50aefb0d8f7e4748