oox: preserve scene3d/lightRig effects on shapes.

Shapes can contain 3D effects like in the following example:

  <a:scene3d>
    <a:camera prst="isometricLeftDown" zoom="150000"/>
    <a:lightRig rig="threePt" dir="t">
      <a:rot lat="0" lon="0" rev="4800000"/>
    </a:lightRig>
  </a:scene3d>

This patch preserves the a:lightRig tag, its attributes and the child
element a:rot using the shape grab bag. It also adds a unit test for
this case.

Change-Id: I66b6de3c2b5ef89223b10da54006e28113b8ba5f
ooxml: Preserve shape 3d effects: z, contour and extrusion

Shapes can contain 3D effects like in the following example:

  <a:sp3d z="488950" extrusionH="63500" contourW="50800"/>

This patch preserves the a:sp3d tag and its attributes using the shape
grab bag and modifies an existing unit test to add this check.

Change-Id: Ice3cae39c71784be0f6c7f2700b07c21a5e1fb6e
ooxml: Preserve shape 3d effects: top and bottom bevel

Shapes 3D effects can specify top and bottom bevels like in the
following example:

  <a:sp3d z="488950" extrusionH="63500" contourW="50800">
    <a:bevelT w="139700" h="88900" prst="cross"/>
    <a:bevelB h="88900" prst="relaxedInset"/>
  </a:sp3d>

This patch preserves the a:bevel* tags and their attributes using the
shape grab bag and modifies an existing unit test to add this check.

Change-Id: I4762111e4d2f75ba2fd3721a126aa324a28a853c