Additions to PHPExcel_Chart_Layout to allow manual 3D rotations

Today I made additions that allow manual rotations of a 3D chart, such as a pie chart. These may not be included in exactly the correct places, but they are useful for me as-is.

Using a layout sample like this...

	$layoutPlotArea = new PHPExcel_Chart_Layout();
	$layoutPlotArea->setManual3dAlign(true);
	$layoutPlotArea->setXRotation(50);
	$layoutPlotArea->setYRotation(0);
	$layoutPlotArea->setPerspective(15);
	$plotArea = new PHPExcel_Chart_PlotArea($layoutPlotArea, array($series1));

Results in XML additions of,,,

	<c:view3D>
		<c:rotX val="50"/>
		<c:rotY val="0"/>
		<c:rAngAx val="0"/>
		<c:perspective val="15"/>
	</c:view3D>