SciDAVis - Improvements SVN-temp

Some improvements regarding const-correctness:

Signals of AbstractAspect and AbstractColumn are emitted from within undo
commands. Hence, changing the originator in reaction to these signals is almost
certainly a bug. In other words, the pointer to the Aspect/Column being changed
is conceptually const.

Likewise, having a filter change its inputs is dangerous and should be
discouraged. SimpleMappingFilter needs some rethinking; if possible in the
context of an actual use case.

- implemented the first draft of the matrix module
(compiles, but still needs work and testing)
- added matrix icons using the same style as the table icons
- some minor changes to Table and related classes

Added installation targets for desktop integration files (.desktop, mime info, icons).

Added French comments to .desktop files and mime package. Thanks to erictanguy.

- Added missing files and options to the modular build system and removed old
build files. Some bits deliberately not ported:
CONFIG+=thread win32:DEFINES+=Qt_THREAD_SUPPORT: We don't use threads.
DEFINES+=QT_PLUGIN: Added automatically if CONFIG contains plugins.
win32:DEFINES+=QT_DLL: We're not building DLLs.
QT+=qt3support: Try to port everything to pure Qt4. If necessary, this flag
can be temporarily added again for individual modules.
- Removed resource.h, which was only used by iPlot.rc, which has been removed.
- Some consistency improvements in Project.
- Started to re-integrate scripting support.

Added XML mime info file according to current freedesktop.org standard.

- implemented portrait/orientation selection for
EPS and PDF export
(closes feature request 1887933: Export graphs to EPS without rotation)

Remark: There is really no point in using QPrinter::Custom with Qt < 4.4,
it will use a standard page size anyway[1]. So I won't fix the stuff
related to custom page sizes until we have Qt and the new
plotting engine with floating point coordinates.)

References:
[1] http://trolltech.com/developer/task-tracker/index_html?method=entry&id=99441

- made the default manual folder customizable via
the project file

Added .desktop files for menu entry and mime type on Linux.

- Extended search for default paths to the manual to include
a) /usr/share/doc/scidavis-<version>/
b) .../manual/index.html in addition to .../manual-<locale>/index.html