User Management Improvements

What's new:

• Admin can add, edit, and delete users using the dashboard
• Improve the role management, available role: admin, editor, author
• And a few improvements, read below

Note for roles:

• admin: has access to all the administration features
• editor: can publish and manage static pages/posts including the posts of other users
• author: can publish and manage their own posts

What's Changed

• Update it_IT.ini by @eagleman in #701
• Update zh_TW.ini to v2.9.5 by @XD9527 in #708

Full Changelog: v2.9.5...v2.9.6