SciDAVis - Improvements SVN-temp

- replaced the green on black data display toolbar by a
status bar at the bottom
Remark: You can copy the text from the
status bar using its context menu.

- fixed some bugs
- modified Double2StringFilter to show empty cells
instead of zeros for empty rows

Fixed Python scripting (broken by renaming).

- started to integrate the new Table class into the
application
Status: It compiles and runs but a lot of functionality
is disabled at the moment, many things are under heavy
construction. At least testing inside the application
is possible now.

- did some left over renaming
- added missing timer stop to main.cpp

- extended the table command test program
- fixed some bugs related to table commands

- implemented several more table commands
- made some additions to Interval and IntervalAttribute
that are used in the new table commands
- updated the table command test program
- some small improvements to TableModel

- Made icon background transparent, which required some other changes in order to go well with different backgrounds.
- Simplified splash screen and added the logo to it.
- Fixed some details.

- improved loading/saving of gzipped project files

- implemented handling of selections in TableView