Bug 207120 Please model provide an API for data type conversion.
Currently, there're two data types: column data type and parameter data type. But they're inconsistent. Could model provide APIs for conversion between the two types. Thanks. In addition: please check the code into head and 2.2.1 branch, because we have a 2.2.1 bug to fix.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/ModuleUtil.java
{
		/**
		 * Wirte the action in to a stream.
		 * 
		 * @param os
		 * @param action
		 * @throws IOException
		 */
		public void write( OutputStream os, Action action ) throws IOException
		{
			writer = new SectionXMLWriter( os, UnicodeUtil.SIGNATURE_UTF_8 );
			writeAction( action, IImageItemModel.ACTION_PROP );
		}
		protected Module getModule( )
		{
			return null;
		}
	}
	/**
	 * Justifies whether a given input stream is a valid report design.
	 * 
	 * @param sessionHandle
	 *            the current session of the report design