Add PDF Support fixes #261 Note, chart output is not enabled

The PDF output isn't the best because PHPExcel does an HTML output and then runs that through the pdf libraries html input and PDF libraries and tables have never gotten along great...  But it does work.

To use charts a chart render library would need to be installed and enabled.  JPGraph is proprietary so I couldn't build it in.

```php
$rendererName = PHPExcel_Settings::CHART_RENDERER_JPGRAPH;
$rendererLibrary = 'jpgraph3.5.0b1/src';
$rendererLibraryPath = '/php/libraries/Charts/' . $rendererLibrary;


if (!PHPExcel_Settings::setChartRenderer(
		$rendererName,
		$rendererLibraryPath
	)) {
	die(
		'NOTICE: Please set the $rendererName and $rendererLibraryPath values' .
		EOL .
		'at the top of this script as appropriate for your directory structure'
	);
}
```