Exporter: Always show basic Export button, change text to clarify

The button displayed above the advanced settings is now 'Export All',
and is displayed even when the advanced settings are visible.

client/my-sites/exporter/exporter.jsx

@@ -25,6 +25,16 @@ export default React.createClass( {
 		const { setPostType, startExport } = this.props;
 		const { postType, shouldShowProgress } = this.props;
 
+		const exportButton = (
+			<SpinnerButton
+				className="exporter__export-button"
+				loading={ shouldShowProgress }
+				isPrimary={ true }
+				onClick={ startExport }
+				text={ this.translate( 'Export All' ) }
+				loadingText={ this.translate( 'Exporting…' ) } />
+		);
+
 		return (
 			<div className="exporter">
 				<FoldableCard
@@ -39,15 +49,8 @@ export default React.createClass( {
 							</h2>
 						</div>
 					}
-					summary={
-						<SpinnerButton
-							className="exporter__export-button"
-							loading={ shouldShowProgress }
-							isPrimary={ true }
-							onClick={ startExport }
-							text={ this.translate( 'Export' ) }
-							loadingText={ this.translate( 'Exporting…' ) } />
-					}
+					summary={ exportButton }
+					expandedSummary={ exportButton }
 					>
 					<AdvancedSettings
 						postType={ postType }