SciDAVis - Improvements SVN-temp

- changed semantics of QString argument of NonLinearFit constructor
from "formula" to "curveTitle" in order to make it consistent with
the other fit classes
- added some constructors to fit classes in order to unify the fit interface
- removed superfluous call to MultiLayer::updateTransparency from
ApplicationWindow::updateLog
- several bugfixes and improvements to the scripting subsystem

- fixed Bug #8465: Nonlinear Fit Form has no cancel button
(the fit dialog has a close button on all 3 pages now)

- merged the classes fDialog and functionDialogui into
one class FunctionDialog as suggested by Ion

Improved the Fit classes following Knut's suggestions.

- Fixes bugs introduced by the new handling of the fit curves.
- Improved the functionDialog.
- Improved the eventFilter of a table header (the Ctrl button functions again when adding columns to the selection) and removed superfluous Table class global constants.

- Fixed crashes on Windows when executing assignments in Notes.
- Python support now compiles with SIP 4.4.5 as well as SIP 4.2.1;
there are still unresolved issues with the versions in between.

- Modified the handling of a result fit curve: if in the user global settings the option "GenerateFitCurve: Uniform X" is checked, the result curve is handled as a FunctionCurve, otherwise the Origin behavior is followed: a hidden table is generated.
- Improved the code in the FunctionCurve class.
- Improved the context menu of the 2D plot curves.

fixed qti.sip to work with SIP 4.4.5

some minor bugfixes

- Added a context menu for the 2D plot curves.
- Updated to the last CVS version of Qwt5