SciDAVis - Improvements SVN-temp

- Improved Python interface (fixed sorting and normalizing, added support for
changing curve style parameters).
- Some minor cleanups.

Cleaned up fitting code a little bit.

- merged missing "const"s from trunk rev 1000

- added *.csv as an extension option for ASCII export
- fixed line wrapping for the formula edits in table
and matrix control tabs
- started implementing validity handling for plots
- merged the column undo fix (ColumnPartialCopyCmd)
- new numeric columns now honor the default number
of digits setting

merged rev 978 from trunk, i.e.:
- fixed/improved column cell validity handling

merged rev 1001 from trunk, i.e.:
- made a better table dimensions dialog
- reordered the table menu a little bit
- fixed the matrix coordinates spin boxes

- made a better table dimensions dialog
- reordered the table menu a little bit
- fixed the matrix coordinates spin boxes

Merged all changes made in the LapPlot SVN repos up to rev 58.
The changes relevant to SciDAVis are:
- new accessor macros
- new project properties adopted from LabPlot
- several missing "const"s added
- fixed undo for cell editing (validity is now correctly undone)
- fixed a couple of compiler warnings
- merged improved table menus and table normalization method
from 0.2.x branch
- several other minor changes

Fixed parameter substitution into formulas of fit curves.

Fixed a minor syntactic error.

- Fixed estimation of parameter errors in case of Nelder-Mead Simplex fitting
with unknown Y errors.

- Fixed FFT filters - cutoffs could fall between real and imaginary part of a
Fourier component, so that this component would (a) have its amplitude
reduced (but not set to zero) and (b) have its phase modified.

pics for manual version 0.2