of generating scalable output. Some libcairo update had caused
the output to use the wrong version of SVG by default, which
generates an SVG-wrapped PNG data block, which is not scalable,
and not what was intended with the "plot svg" command.
and incorrect call to cairo_set_source_rgba which is in an unused
function and has no effect except with versions of Tcl less than 8.6
where "load -lazy" is not available and unknown functions cause
immediate exit. Cleaned up remaining references to OpenGL in the
Cairo code, and updated the copyright and acknowledged Chuan Chen, who
coded the Cairo interface. No attempt yet to deal with memory leaks
caused by calling Cairo "create" functions without the accompanying
"destroy" functions.
the python preprocessor version, the techfiles and .magicrc file
will get the correct arguments, without affecting the use of CPP
in the configure script.