Latest developer build

Latest developer build of NetsuShelf with the latest fixes.
To install the Addon pick the file suitable for you,

• NetsuShelf1.0.12.8.Firefox.zip for Firefox
• NetsuShelf1.0.12.8.Chrome.zip for Chrome

Installation instructions: https://github.com/NetsumaInfo/NetsuShelf/tree/ExperimentalTabMode

Full Changelog: 1.0.12.0...developer-build