This code was simply missing, since the table border properties are
already stored and displayed.

The table properties are streamed out at the start of the table for
non-nested tables, and at the end of the table for nested tables.  The
assertion caught the fact that I didn't get the start of the table row
for nested tables before trying to stream out the properties.

The call to ME_GetTableRowStart will handle both of these cases by
getting the table row start paragraph and asserting that it is found.
This call was also the reason for removing the const qualifier on one
of the parameters.

Static sized buffers are used for storing the colours and fonts, so
there needs to be a check to prevent these buffer from overflowing.

Previously the paragraph and cell border properties were lost when
deleting the text, then undoing the deletion. This would cause tables
to lose the colour and width of the table border.