Applying the indentationChars and lineBreakChars as config properties

[Sa'ar Zac Elias]

In the htmlwriter plugin, there are properties called indentationChars and lineBreakChars. these properties controls the markup of the output. i think it is necessary to make them config properties, so the developers will be able to change them within the regular mode and not just through the source mode.

[Alfonso Martínez de Lizarrondo]

It's already possible to adjust those properties as the examples show:

 * // Use two spaces for indentation.
 * editorInstance.dataProcessor.writer.indentationChars = '  ';

 * // Use CRLF for line breaks.
 * editorInstance.dataProcessor.writer.lineBreakChars = '\r\n';