Set development to 1.5.5-SNAPSHOT
Issue #174: Fix focus and sliding menu for devices connected to a TV

Some HDMI sticks don't identify themselves and Android TV devices.  To work
around this, added a preference option that can be toggled to let the app
it is in TV mode.  Google TV and Android TV related devices get this set
automatically.
Issue #176: Provide optimized displays for XLarge devices.

This includes new layouts for XLarge devices like Kindle Fire HD and HDX, as
well as Nexus 10 devices.
Release 1.5.5
Reset versiong to 1.5.5-SNAPSHOT
Release 1.5.5