SciDAVis - Improvements SVN-temp

- 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

- fixed empty output format list

- updated all dialogs ported to Qt4 in this branch
with the changes from trunk rev. 7 to 27

- added version suffix to about dialog and thereby set
the version string to "0.8.6alpha1"

- seems I forgot to convert qtiplot.pro to DOS format