Added a Q3FileDialog in canvas.cpp:Main::exportCellData() inquire
where to write the exportCellData.

--
user: Michael Guravage <michael.guravage@cwi.nl>
branch 'default'
added doc/Makefile
added doc/stylesheet.json
added doc/v1.html
added doc/v1.pdf
added doc/v1.rst
added src/leaficon.png
changed src/ChangeLog
changed src/canvas.cpp