#169 wxwidgets device: incorrect interactive rendering of example 17

[Alan W. Irwin]

There is no "interactive" display of example 17 as this "chart recorder" example gradually progresses like a video. Instead only a snapshot of the last frame of this video is shown. To see how this plot should really be displayed as a video, look at results from such interactive devices as xwin, xcairo, and qtwidget. (I assume the wincairo and wingcc devices display this video example properly as well, but I cannot confirm that at the present time.)

[Phil Rosenberg]

Fixed by commit 81fafd2