NVIDIA Shield Beta 2

Pre-release for testing new NVIDIA Shield functionality
See discussion #47

v2.0.0-beta2

Fixed the following reported items:

• Default compatibility mode does not seem to be defaulting properly, causing most buttons to fail
• Power button is unreliable in "Strong" compatibility mode for Shield devices
• Shield buttons do disappear when removed from YAML, but do not yet have a removal option through the GUI
• YouTube button does not launch the YouTube app on Shield devices

Known issues still open/unresolved:

• Visible device name feature is not yet complete as it breaks the layout of the Shield remote
• Original Shield remote style is not yet available, only the latest version
• Updated documentation is not yet written

Full Changelog: v1.11.4...v2.0.0-beta2