Fix: Snooze list now appears above all else
Cross platform UI cleanup

* Fixed chart not sliding with drawer open/close.
* Shrunk red snooze/warning button to fit the space better.
* Fixed time overlapping red warning button on small screens (by hiding
it).
Red alert button position adjustments.

Makes it look a little better.
Merge pull request #49 from nightscout/rebase/settings

Rebase/settings