SciDAVis - Improvements SVN-temp

Some fixes to selection of Graphs.

- Improved the interpolation and implemented it in a new class.
- Added files forgotten in the last commit.

-First implementation of the abstract Filter class, to be used as base class for all data analysis operations.
-Implemented numerical integration/derivation using this approach.
-Fixed some bugs linked to the display of the legends in 2D plots.
-Did some cleaning in the headers of ApplicationWindow.cpp.

- Fixes bugs 010440, 010320 and 010154.

- Improved the export of 2D plots.
- Fixed a small bug concerning the restoring of notes from project files.

Minor fixes to moving layers and markers.

- Improved the ImageDialog by replacing the ChainButton with a simple QCheckBox.
- Removed some obsolete code from MultiLayer class: this also prevents flickering when selecting objects on a plot.

- Fixed bugs in InterpolationDialog, added the interpolation operation to the Python interface and fixed bug #10169.
- Improved setColor() method in Fitter.cpp.
- Fixed resizing of MDI windows through the ImageDialog.
- Improved the layout of the ImageDialog.
- Improved the sorting of single columns in Tables: now text columns are also sorted.

- Dropped support for SIP < 4.4, which is not even supported by PyQt4.
- Sorting of table columns slightly improved and added to qti.sip.
- Fixed ScriptWindow (the setVisible() signal was masking QWidget::setVisible()).
- Some minor fixes and improvements.

- Selection, moving and resizing of layers and plot markers rewritten.
- Reverted some changes of r341 that broke positioning of image markers.
- Some documentation added.
- Removed superfluous include from muParserScripting.cpp.