This version is unreleased and can be used.

- Replace Material Droplist with native HTML events
- Remove simple-drop-list element; Cloze elements now use the normal 
DropList element
- Add example units

- add hotspot image element
- raise version to 3.8.0

- Replace asynchronous child processes with synchronous processes
- Add shortcuts to package.json

Move label creation to ElementFactory.

No way has been found to have an abstract static method for 
OptionElement's label generation, therefore silence the linter.
Same for getElementComponent.

#298

This reverts commit da09ac1e.

This way elements can handle their logic themselves without having to
rely on outside utility classes.

Also restructure files in common in a more logical way.

- upgrade @ngx-translate/core
- upgrade rxjs
- upgrade testcafe

- run npm update

Build and deploy script are written in bash for now as the syntax is
far easier and cleaner. Might be changed in the future as this requires
a Linux environment with bash available.

Deployment happens as version 9.9.9, because Teststudio does not accept
players and editors without semantic versioning.

The Dockerfile is the image used for building and deploying the app.

The package karma-spec-reporter is to show more info about run tests on 
the console.

Numbers on the test files refers to the version (2 digits for minor; 
patch number ignored).

New name: richTextOptions

Unit definition version has been raised accordingly.