FORGE-1646 Add Highlighter API for color coding output

Hightlighter API wrap the Syntax coloring part of forge-text.

Supports color coding for:

* HTML (with inline JavaScript/CSS)
* JavaScript
* CSS
* Java
* JSON
FORGE-1646 Add Highlighter support to CatCommand based on FileName type
Merge pull request #409 from aslakknutsen/highlight

FORGE-1646 Add Highlighter support to CatCommand based on FileName type