[R] Cairo on windows

[Moisan Yves]

> My experience is that cairoDevice is a lot slower than Cairo,
especially 
on Windows, and about equally flaky.  If you see how many layers are 
involved with Cairo on Windows you will not be surprised.

Actually, I ended up trying to load deviceCairo simply because it was
the only other package with the string "Cairo" in it besides "Cairo"
itself ;-).  I suspected some interaction between the two libraries
(deviceCairo and Cairo) so that's why I tried to load it hoping it would
solve the flakiness of the CairoWin display.

> If all you need is semi-transparency support I suggest you try R 2.6.0
RC
which supports it in the windows() device.

Thanx for the tip.

Yves Moisan