Bug 152834 support HTML description of the template
The template descrition is a fragment of HTML, use that fragment to render the template in HTML.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/content/IForeignContent.java
public final String IMAGE_TYPE = "binary/image";
	
	public final String UNKNOWN_TYPE = "binary/unknown";
	
	public final String VALUE_TYPE = "binary/value";
	/**
	 * the orginal format of the object. such as: "text/html", "text/rtf",
	 * "xml/svg" etc.
	 * 
	 * @return type of the content
	 */
	public String getRawType( );
	void setRawType( String type );
	/**
	 * the orignal content describe in raw format.
	 * 
	 * @return Returns the content. Caller knows how to cast this object
	 */
	public Object getRawValue( );
	void setRawValue( Object value );
	
	/**
	 * @return Returns the altText.
	 */
	public String getAltText( );
	public String getAltTextKey( );
	public void setAltText( String altText );
	public void setAltTextKey( String key );
}