Log Message:
(graphics/R-Cairo) Updated 1.5.10 to 1.5.12

1.5-12
    o	use pkg-config --static --libs when needed

    o	adapt to API changes in R 4.0.0, also improves symbol
	placement in recent R versions

1.5-11	(2020-02-26)
    o	fixed missing PROTECT() (thanks to Tomáš Kalibera)

    o	minor changes to remove R CMD check warnings