ooxml: fix cell theme color and shade preservation

The cell property w:shd was not being properly preserved when the
shade value was different from "clear". The shading affects the cell
color and the exporter was not taking that into account when comparing
the cell color with the original color to know if the user had changed
it.

Besides, we were not preserving the attributes themeColor, themeTint
and themeShade.

I have modified the existing unit test testTableThemePreservation to
add a check for those new attributes.

Change-Id: I06d2e668486803cba039eacb717a69413bd5a1df
oox: Integrate Shape3DProperties and Scene3DPropertiesContext

Code for these two classes was already present but it was commented
out or left outside of the build system because it didn't even
compile. I've brought it back and made it compile, but it has no use
yet. The goal is using it to preserve 3D transformations.

At scene3dcontext.cxx I removed the text chunks found in the middle
of the source and corrected some mistakes; I also modified the
conversion of "fov" attribute.

At shape3dproperties.hxx I removed all the struct members because
they seemed to have been copied&pasted from another file, and added
only those members that made sense. Removed useless function
definitions.

Change-Id: I2c00ea638e1a4fb1a3820bc4c322488296d3e6d7
oox: preserve scene3d/camera 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:scene3d>

This patch preserves the a:camera tag and its attributes using the
shape grab bag. It also adds a unit test for this case.

Change-Id: Ic6a78031d2e1fb84a2bacd97b5cc9c55d9dbaa95
oox: preserve camera rotation on shape 3D effects.

Camera options in shape 3D effects can have rotation settings like in
the following example:

  <a:camera prst="perspectiveRelaxedModerately" zoom="150000">
     <a:rot lat="19490639" lon="0" rev="12900001"/>
  </a:camera>

This patch preserves the a:rot tag and its attributes using the
shape grab bag. We created the class Scene3DRotationPropertiesContext
to be piled on top of a Scene3DPropertiesContext and process the
contents of the child item. It also adds a unit test for this case.

Change-Id: Id6bf58ad05fe5b49061619b6750ed0658badc9af