Minor bug-fix

Bugfixes, improvements, refactoring

- Bugfixes: 
Issue with expanding editor for creating new items. 
Not being able to highlight text in JSON view.
Glitch in splash screen on Linux.

- Improvements: 
Enhanced editor for creating new items. Now showing error message and highlighting on illegal JSON.
Tooltips on icons for clarification and on menu items for seeing full name on truncated.

Refactoring:
- Better generalized solution for tooltipping.
- General refactoring and code cleanup.

New feature added, bugfixes, improved styling, update readme

Feature added: Ability to add new elements to root of subsections
Bugfixes: Scroll issue with console.
New REST call structure implemented, so elements from datastore is now requested in individual calls.
(Allows lightstates to be shown under scenes)

Bugfix, test and config setup.

Bugfix: Now automatically refreshes during the lifecycle of the app.

Test: Set up snapshot tests with Jest

Config: Set up Travis CI with Node