SciDAVis - Improvements SVN-temp

- Fixed bug #2982928 (Scidavis crashes at Polynomical Fit) by making sure that
the interval Filter operates on is normalized.

- Removed files with unclear license. Removed code was used only for
Savitzky-Golay smoothing.
- Reimplemented Savitzky-Golay smoothing from scratch, based on information
found at http://www.statistics4u.info/fundstat_eng/cc_filter_savgol_math.html
and routines provided by the GSL. The new implementation features improved
handling of values near the endpoints of the input data; namely, instead of
effectively zero-padding the data, the smoothing polynomial obtained from a
fixed window is used to compute the output values in question.

- Replaced news import via deprecated and broken SF.net interface with a simple RSS adapter.

- Added missing license note to globals.cpp.

- Added copyright/license header to files written by Ion Vasilief, after
consulting him on the matter. Compare QtiPlot r1656.

- Removed unused file resource.h.

- Added copyright/license header to some files written entirely or primarily by me.

- Update of Czech translation by Pavel Fric.

- Cleaned up build system. Added options for disabling some features which are
frequently undesirable when integrating SciDAVis in a Linux distribution,
such as checking for updates. Added presets for common setups (end user
installing from source, packaging, self-contained binaries) which can be
selected on the command line (e.g. "qmake PRESET=linux_package") without
having to edit/patch a configuration file.

- Changed link for Slackware packages (until linuxpackages.net gets updated again...).