SciDAVis - Improvements SVN-temp

- Derived the Fit class from the abstract Filter class.
- Did some cleaning in the graph.cpp (removed spurious data analysis related methods).

- Fixes bugs in the Axis Dialog.
- Fixes the Format Menu Bar for 2D plots.
- Removed the superfluous insertFirstLayer() function from the MultiLayer class.
- Improved the Differentiation class.

Obfuscated email addresses in file headers in order to reduce exposure to spam bots.

Some small fixes.

- Fixed the standalone help and improved the parsing of command line options.
- Restored the behavior of TextDialog: the real font is now again displayed in the text edit window, but with a fixed size of 12 points.

- Added missing files.

- Implemented Smoothing and FFT filtering of 2D curves in stand-alone classes.
- Same for FFT + a first attempt to unify FFT on tables with FFT on 2D plots.

- promoted version number to 0.9.0beta1
- fixed a typo in the German translation
- simplified the way files are loaded
from the command line (and fixed several
bugs by doing that)
- fixed the progress dialog behavior in
ApplicationWindow::openProject()
- extended the handling of command line arguments
(type "qtiplot -h" for info)
- fixed the path where QAssistant is looked for
(it is $PATH or %PATH% now, respectively)
- moved version number/release date constants
into a seperate header file 'globals.h'

- Fixed crashes triggered by right-clicking on a SelectionMoveResizer.
- Clicking on an axis selects and raises a layer, anywhere else just activates it.

- adjusted the context names in all translation files
- fixed a crash when loading project files
- added japanese translation to qtiplot.pro