Apparently this special case in lcl_PaintLeftRightLine for printer
output devices is no longer necessary with the new drawing layer borders
and causes the vertical border lines to be far too short, leading to
visible gaps in the PDF.
(regression from 0f0896c2)

This re-implements the merging that was done by SwLineRects::AddLineRect,
SwLineRect::MakeUnion with the drawing layer border lines.
This is used to merge borders of paragraphs and of tables that have the
"separating" border-model, which fixes both the tiny dividing gaps
between successive borders in the second bugdoc and the weird subtly
differently rendered successive borders in the first bugdoc.
(regression from 0f0896c2)

Gradients with start==end got us zero steps, thus no fill at all.
Funnily this was wrong since pre-3.0 or somesuch.

sd/filter

sd

/sd/.../grf and html

with this you can now do:

 ./autogen.sh --enable-debug="sw sc"

and your build will have debug version of the libraries sw and sc, but a
non-debug build elsewhere. This currently only works for libraries. It would be
also possible to extend that to excutables, but that would need explicit in the
enable-debug switch then:

 ./autogen.sh --enable-debug="Library/sw Library/sc Executable/mkunroll"

so I dont know if it is worth it.

sd ... filters

/sd/../core

in sd/ui

The line hight for the dialog box was not high enough; changed it from 8
to 10.