SciDAVis - Improvements SVN-temp

- Simplified import of ASCII files.
- Added ExtensibleFileDialog, a generic extension mechanism for QFileDialog.

- Fixed table import with current locale

Fixed bug in Table::importASCII(), due to the behavior of QTextStream regarding end-of-line character, which is problematic for reading Mac OS X generated ASCII files.

Implemented Feature Request #3441: Add/remove curves: Show only this folder.

Fixed bug in ApplicationWindow::windowsList(),
introduced by my previous commit.

Fixed bug 011178 "Add curve: duplicated entry" and bug 011176.

- Fixed bugs in Matrix::cellEdited() and Matrix::saveCellsToMemory().
- Implemented the possibility to update the decimal separators in existing Tables/Matrices when the user changes the locale.

- Fixed crash then table with big column comment is opened

- Implemented Feature Request #3433; Column Options -"Enter" behaviour.
- Fixed the display of the "<</>>" button in PlotDialog on Mac OS X.

- Fixed bug in Matrix::saveText()