Added a text clipping option to the Cairo devices. The user can now turn on text clipping by specifying text_clipping=1.
Added a text clipping option to the Cairo devices. The user can now turn on text clipping by specifying text_clipping=1.

svn path=/trunk/; revision=7812

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