SciDAVis - Improvements SVN-temp

- Added an Origin-like feature: when plotting a list of columns, if some columns are declared as having yErr or xErr type, they are plotted as error bars.

- tagging version 0.8.7-3

- improved the Python interface to folders
- added documentation for the above

- Fixed bug in NonLinearFit class: setting only one parameter caused crashes.
- Modified TableStatistics behavior so that the user can use them directly for plotting.
- Fixed restoring geometry and creation date of TableStatistics from project files.

- table statistics now react to columns being deleted or renamed

- Defined a new "fit_scale_errors" option in the user global settings and added this option to the configDialog.
- Fixed translation issues in configDialog and translation of the ScriptWindow when the language of the main application is changed by the user.
- Upgraded French and Spanish translations.
- Fixed some compile issues on Windows due to new code in TableStatistics.

- column / row statistics are automatically updated when the base table
is edited
- fixed some sanity checks in ApplicationWindow
- "exit -> yes (save changes) -> cancel" now cancels the exit instead of
discarding the changes
- added support for folders to Python interface
- some minor fixes

- Improved install instruction concerning SIP path.
- Fixed some issues with the translation of several menu items.

- Fixes some crashes due to the scales handling in 2D plots.
- Fixes some bugs in drawing of inward ticks and of the plot canvas frame introduced by the last CVS changes in Qwt.

- Added an option to scale fit errors with sqrt(chi^2/DoF) using the Non-Linear fit dialog or the scripts.