Add actor traits

[marvin9257]

• Please check if the PR fulfills these requirements

• We use semantic versioning (https://github.com/semantic-release/semantic-release to be specific), so follow https://github.com/angular/angular.js/blob/master/DEVELOPERS.md#-git-commit-guidelines EXCEPT, don't use 'feat:' if you're not me. Stepping major versions until 1.0 is a deliberate decision (after that, it'll be full semantic versioning.)
• Docs have been added / updated (for bug fixes / features)

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)
  Add feature - allow actors to have traits. This addresses issue Implement Traits #272

• What is the current behavior? (You can also link to an open issue here)

No ability to use traits other than in actor notes

• What is the new behavior (if this is a feature change)?

Creates a new item type - trait - that shows on actor info tab.

• Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?)

I don't think so - but there will be some missing translations

• Other information:

[marvin9257]

This is the first time changing the HTML and CSS files. So please check my homework. I can't find any errors.

[xdy]

Added a fix to en.json and merged manually, so closing.