ANNOUNCE: GtkPlot-3.1

[Adrian Feiguin <feiguin ifir ifir edu ar>]

GtkPlot-3.1
===========

- New action:
  Select region with the mouse. The signal "select_region"
  will return the coordinates of the selected area: 
  xmin, xmax, ymin, ymax. Useful if you want to implement zoom.

- Text with justification.

- Centered axis titles.

- Bugfixes in gtkplotps.


GtkPlot-3.0
===========

- New Font policy. 
  Fonts are identified by a user_name and/or the standard PostScript name.
  The 35 names are listed in gtkplotfont.h
  All function requiring font settings need the font name and
  font height instead of a GdkFont.
  You can add your own user fonts using gtk_plot_font_add(...) declaring
  both names and two possible Xfonts used to display them on the X window.

- PostScript Driver.
  Completely separated from the widget main code in gtkplotps.
  Exporting functions:
     * gtk_plot_export_ps
     * gtk_plot_layout_export_ps
  (It would probably need some fixes, I'll be waiting for your reports).
  The demo program generates plotdemo.ps as example.

- Some internal changes (bugfixes and enhancements).

Thanks to Alexander Larsson and Arjan Molenaar, authors of DiaCanvas and
Dia, for allowing me to borrow some ideas from his code for the 
PostScript driver and fonts handling.

Special thanks to Roberto Alameda <ral1@ibm.net>, author of FontViewer 
http://www.geocities.com/SiliconValley/Foothills/1458/
for his illuminating ideas and helpful tips about fonts.

GtkPlot-2.0
===========

Sorry for not being very explicit, but I'll describe only an outline of 
the latest changes because is difficult to keep track of all of them.
To move from 1.x to 2.x you'll have to change some few function calls
concerning to the attributes settings. It's easy to realize the changes
during compilation time, just take a look at the headers when you get an error.

- New GtkPlotCanvas widget which allows DnD. See demo.

- Lots of changes in internal routines for optimization and versatility. 

- Changed some function calls.
  Sometimes you'll need to give a GdkColor * value. If you set NULL,
  means using defaults: black for foregrounds and transparent for backgrounds.
  If you set gc == NULL, means using default gc. 

- New functions added.
  gtk_plot_refresh,
  gtk_plot_show_labels,
  gtk_plot_layout_put_text,
  etc, etc.

- typedef GtkPlotFunc for drawing functions.

- New signals: plot->moved, plot->resized.
  Your signals handlers must return TRUE if you want the changes 
  to be accepted. Same is valid for GtkPlotCanvas signals.

- Some minor bugfixes.
  gtk_plot_put_text. (I recommend gtk_plot_layout_put_text, instead).
  Fixed rounding errors in axis, ticks marks, and grids drawing routines.

- New demo program.


GtkPlot-1.1
===========

- You can change background color for gtkplot and gtkplotlayout using

  gtk_plot_layout_set_background(GtkPlotLayout *layout, GdkColor color);
  gtk_plot_set_background(GtkPlot *plot, GdkColor color);

- Many functions modified to set foreground and background colors for
  labels and titles.

- Fixes in the GtkPlotLayout scrolling.