Fixes to ZipArchive cass when PCLZip being used

Fixes to default arguments when typehinted arguments in Chart writer are null values
Fix to gitignore for Examples folder/subfolders

Examples/.gitignore

@@ -2,4 +2,11 @@
 *.xlsx
 *.csv
 *.jpg
-*.pdf
+*.pdf
+*.htm
+*.html
+*.log
+!.gitignore
+!data/**
+!images/**
+!templates/**

src/PhpSpreadsheet/Shared/File.php

@@ -76,7 +76,8 @@ class File
             $zipFile     = substr($pFilename, 6, strpos($pFilename, '#') - 6);
             $archiveFile = substr($pFilename, strpos($pFilename, '#') + 1);
 
-            $zip = new ZipArchive();
+            $zipClass = \PHPExcel\Settings::getZipClass();
+            $zip = new $zipClass();
             if ($zip->open($zipFile) === true) {
                 $returnValue = ($zip->getFromName($archiveFile) !== false);
                 $zip->close();

src/PhpSpreadsheet/Shared/PCLZip/gnu-lgpl.txt

@@ -501,4 +501,3 @@ necessary.  Here is a sample; alter the names:
 
 That's all there is to it!
 
-

src/PhpSpreadsheet/Shared/ZipStreamWrapper.php

@@ -88,7 +88,8 @@ class ZipStreamWrapper
         $url['fragment'] = substr($path, $pos + 1);
 
         // Open archive
-        $this->archive = new ZipArchive();
+        $zipClass = \PHPExcel\Settings::getZipClass();
+        $this->archive = new $zipClass();
         $this->archive->open($url['host']);
 
         $this->fileNameInArchive = $url['fragment'];

src/PhpSpreadsheet/Writer/Excel2007.php

@@ -351,7 +351,8 @@ class Excel2007 extends BaseWriter implements IWriter
                         $imagePath = substr($imagePath, 6);
                         $imagePathSplitted = explode('#', $imagePath);
 
-                        $imageZip = new ZipArchive();
+                        $zipClass = \PHPExcel\Settings::getZipClass();
+                        $imageZip = new $zipClass();
                         $imageZip->open($imagePathSplitted[0]);
                         $imageContents = $imageZip->getFromName($imagePathSplitted[1]);
                         $imageZip->close();

src/PhpSpreadsheet/Writer/Excel2007/Chart.php

@@ -126,7 +126,7 @@ class Chart extends WriterPart
      *
      * @throws  \PHPExcel\Writer\Exception
      */
-    private function writeTitle(Title $title, $objWriter)
+    private function writeTitle(Title $title=null, $objWriter)
     {
         if (is_null($title)) {
             return;
@@ -171,7 +171,7 @@ class Chart extends WriterPart
      *
      * @throws  \PHPExcel\Writer\Exception
      */
-    private function writeLegend(Legend $legend, $objWriter)
+    private function writeLegend(Legend $legend=null, $objWriter)
     {
         if (is_null($legend)) {
             return;
@@ -226,7 +226,7 @@ class Chart extends WriterPart
      *
      * @throws  \PHPExcel\Writer\Exception
      */
-    private function writePlotArea(PlotArea $plotArea, Title $xAxisLabel, Title $yAxisLabel, $objWriter, \PHPExcel\Worksheet $pSheet, Axis $xAxis, Axis $yAxis, GridLines $majorGridlines, GridLines $minorGridlines)
+    private function writePlotArea(PlotArea $plotArea, Title $xAxisLabel=null, Title $yAxisLabel=null, $objWriter, \PHPExcel\Worksheet $pSheet, Axis $xAxis=null, Axis $yAxis=null, GridLines $majorGridlines=null, GridLines $minorGridlines=null)
     {
         if (is_null($plotArea)) {
             return;
@@ -361,7 +361,7 @@ class Chart extends WriterPart
      *
      * @throws  \PHPExcel\Writer\Exception
      */
-    private function writeDataLabels($objWriter, $chartLayout)
+    private function writeDataLabels($objWriter, Layout $chartLayout=null)
     {
         $objWriter->startElement('c:dLbls');
 
@@ -1404,7 +1404,7 @@ class Chart extends WriterPart
      *
      * @throws  \PHPExcel\Writer\Exception
      */
-    private function writeLayout(Layout $layout, $objWriter)
+    private function writeLayout(Layout $layout=null, $objWriter)
     {
         $objWriter->startElement('c:layout');