SciDAVis - Improvements SVN-temp

- code evaluated or executed in a ScriptEdit uses the correct context
- users can now set local variables also when evaluation code (e.g. when
setting column/matrix values)
- fixed bug that kept errors from being reported when evaluating expressions
in a ScriptEdit
- fixed superfluous-newline bug in restore of axis formulae

- Updated to the last version of liborigin
- Improved saving state of the dock windows and tool bars
- Improved import of Origin projects (arrange tables in cascade)
- Fixed bug in plotDialog (crash when user deletes last curve using the Key_Del)

- ported ApplicationWindow::saveSettings und ::readSettings to Qt4

Changes to ApplicationWindow:
- added "Visit QtiPlot forums" to help menu
- added "Report a bug" to help menu
- ported open_browser() to Qt4 and added more browsers

- fixed compiling errors from revision 42

Added the "Search for &Updates" item to the Help menu

- moved setWindowTitle("QtiPlot - untitled") from main.cpp to ApplicationWindow and added tr() to it
- fixed problems with changing the application style
- fixed missing window borders for tables, matrices, plot windows and notes

- added headers to almost all source files
- added doxygen short description to most classes
- applied qt3to4 to all source files in src
- merged in all dialogs from the "port_dialogs_to_qt4" branch that are fully ported
- ported all code lines to Qt4 that caused compiling errors (a lot)
Status of the QtiPlot Qt4 port:
- compiles without errors (using Qt3Support lib)
- it runs, but is very unstable and a lot of features don't work
- Qwt based functionality still disabled (commented out)

- renamed "Do It" and "Do All" to "Execute" and "Execute All", respectively
- fixed undo for tables (matrices did never support it...)
- fixed support for old file formats (untested); cleaned up related code
- added the functions ceil, floor, log10, mod, pow and sum to
muParserScripting
- gotten rid of some compiler warnings

- changed file format to allow multi-line formulae for table columns and
matrices
-> undo broken for tables and matrices!
-> support for old file formats may be broken, too!
- changed file format to allow multi-line axis formulae in graphs
- several minor fixes