20190120.0

What's Changed

• Optimizes image assets (#2499) @frenck
• Deep clone config (#2496) @bramkragten
• RTL fix for precipitation (#2495) @yosilevy
• Update demo-hui-entity-button-card.ts (#2503) @Tontze
• Add demo (#2502) @balloob
• Upgrade Lit Element to RC3 (#2504) @balloob
• Update WC polyfills (#2505) @balloob
• Update lovelace.ts (#2509) @kernehed
• Update entities.ts (#2508) @kernehed
• Make edit-dialog look ok on mobile (#2501) @bramkragten
• Update entities.ts (#2510) @kernehed
• Fix demo translations (#2511) @balloob
• Add teachingbirds demo (#2516) @balloob
• Remove ids from demo configs (#2515) @bramkragten
• Edit dialogs for mobile (#2513) @bramkragten