Bug 119331 Library - name space terminology and behavior
During BIRT 2.0 library feature review meeting the following change was decided. - Change the term namespace to 'prefix' - By default use the library name as the prefix ( namespace ); the dialog to input prefix should be prompted only if hte auto generated prefix is not unique.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/util/UIUtil.java
* Convert the give string to Model style
	 * 
	 * @param string
	 *            the string to convert
	 * @param trim
	 *            specify if the string needs to be trimmed
	 * @return the string, or null for an empty string
	 */
	public static String convertToModelString( String string, boolean trim )
	{
		if ( string == null )
		{
			return null;
		}
		if ( trim )
		{
			string = string.trim( );
		}
		if ( string.length( ) == 0 )
		{
			string = null; 
		}
		return string;
	}
	/**
	 * Returns the width hint for the given control.
	 * 
	 * @param wHint
	 *            the width hint
	 * @param c