vcl: renamed OutputDevice::PaintLineGeometryWithEvtlExpand()

I asked on the LO dev mailing list what Evtl means and what is being
expanded, and Michael Stahl kindly responded:

>  "Evtl" usually means German "eventuell" which means "possible" or
>  "optional" (i.e. totally different meaning from English "eventual").

So in other words, it means paint using line geometry and optionally
expand. Or in other words, it just draws a line using a B2DPolyPolygon.
Thus, I have renamed it to drawLine(), which is a private function of
OutputDevice. I think this makes it somewhat clearer :-)

Change-Id: I7eec23c61eda9dc1074922f5f2f67eacbc7fd725
Reviewed-on: https://gerrit.libreoffice.org/12264
Reviewed-by: Chris Sherlock <chris.sherlock79@gmail.com>
Tested-by: Chris Sherlock <chris.sherlock79@gmail.com>