Bug 127354 For template, relative path to template image does not work
Steps to reproduce: 1. Create a new template. 2. In the wizard, in Template Image, type a relative path to an image. For example, use an image in the project directory in which you are creating the template. Expected: It works. Actual: Error "Image file '<file name>' does not exist" shows in the UI. If you go ahead and create the template anyway, you cannot publish to the template folder, because Finish is not enabled.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ImageBuilder.java
Composite previewArea = new Composite( composite, SWT.BORDER );
		GridData gd = new GridData( GridData.FILL_BOTH );
		gd.widthHint = 250;
		gd.heightHint = 300;
		previewArea.setLayoutData( gd );
		previewArea.setLayout( new FillLayout( ) );
		previewCanvas = new ImageCanvas( previewArea );
	}
	private void switchTo( int type )
	{
		if ( type == selectedType )
		{
			return;
		}
		selectedType = type;
		Control[] controls = inputArea.getChildren( );
		for ( int i = 0; i < controls.length; i++ )
		{
			controls[i].dispose( );
		}
		clearPreview( );
		switch ( type )
		{
			case URI_TYPE :
				swtichToExprType( );
				break;
			case EMBEDDED_TYPE :
				swtichToEmbeddedType( );
				break;
			case BLOB_TYPE :