** Added fieldPrefix variable into HtmlMaterialProcessingContext (can be
used to prepend prefix into processed fields)
** Changed HtmlMaterialEmbedListener to prepend prefix is defined
** Changed HtmlMaterialEmbedListener to ensure field name unicity
** Changed HtmlMaterialEmbedListener to encode field names
** Changed WorkspaceHtmlMaterialBackingBean to prepend fields with
workspaceMaterialId 
** Commented out deprecated answer saving mechanism from
WorkspaceHtmlMaterialBackingBean