If the lines are created with MOVETO, LINETO, LINETO...
then Line Join NONE is applied. As a result the charts are looks ugly,
with the holes inside it.
For example:
https://bugs.documentfoundation.org/attachment.cgi?id=179962
and
https://bugs.documentfoundation.org/attachment.cgi?id=179837
Additinally commit changed default line join style to miter,
as during experimenting with MS Paint and MS Word,
it appear that default Join Style is PS_JOIN_MITER and
Line Cap is Flat/Butter.
The PDF export tests has been updated, as there is less number
of PDF object after using joiners.
The size of the exported tdf145873.pptx to PDF,
was slighltly decreased from 22.8kB to 22.0KB
Change-Id: I131cc3c5e90f827d67d2360eb18167eed6315abb
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/133624
Tested-by: Jenkins
Reviewed-by: Bartosz Kosiorek <gang65@poczta.onet.pl>
32cb4e4fe5