To fix some errors, need to change svx::frame::Array conversion
to Primitives, especially regarding handling of merged cells.
These make problems in the currtent form where the full extended
merged cell tries to be converted. This is bad for cropped stuff
and also wrong for double-line stuff attaching to a merged cell.
The solution is to handle cells single and merge created primitives
which is more expensive but will work. This will involve special
handling for X-Ed (crossed) and 'roated' Cells. Also need to be
very careful since all this is used in the meantime for all
visualizations of Tables in multiple apps/situations.

Change-Id: If0652a3ba97a6f27dd5d782ea22b1514303f3710