yPlot Code

Get rid of debug output of YPLOT_EXTENSION_FILES_DEPENDS.

Move from standalone executable to dynamically loaded plug-in.

Debian bug workaround not needed for this method so get rid of it as well as
main.c (which was required only for the workaround).

Implement autoloading (which is needed if you don't want the dynamically
loaded plug-in method to be a pain).

Reorganize to do almost everything at run time so that can handle file
dependencies properly.

Add a note about the equivalence of the new yplot command to the old yplotl
command.

Empty the svn:ignore property in expectation of a clean source tree.

Empty the svn:ignore property in expectation of a clean build tree.

New directions based on the new CMake-based build system.

yplot_instructions.i is not required any more since I am dropping forced
portrait mode in favour of simply using the -portrait option to yplot.

yplotl_instructions.i is not required any more since its default landscape
instructions have already been incorporated into yplot.i.

Both files had introductory lines which were related to yorick-1.5.x, but that
is not supported any more, and yplot is now built on top of yorick-2.x,
instead using the plug-in command.

Switch to new plug-in style for Yorick-2.

Implement default landscape startup following what was done with
soon-to-be-removed yplotl_instructions.i.

Call to PLplot's deprecated plParseOpts changed to c_plparseopts to get rid
of deprecation warnings.

rename yplot_body.i to yplot.i in preparation for new yplot which defaults
to landscape mode just like PLplot.