Fix indentation.
Fix indentation.

Make DEFAULT_ALL_DEVICES ON prevail over DEFAULT_NO_DEVICES.

Implement DEFAULT_NO_QT_DEVICES and DEFAULT_NO_CAIRO_DEVICES.

svn path=/trunk/; revision=10092

FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot