Delete the glm's new feature from release notes

doc/release_notes.tex

@@ -582,9 +582,6 @@ \subsection*{New Features}
 the gaze x \& y coordinate units on the y-axis.
 \item \texttt{pspm\_extract\_segments }can be used now with raw data and
 thus be called easily within another function.
-\item \texttt{pspm\_glm }has a new option (\texttt{model.centering}) which
-controls whenever mean centering is applied to convoluted X data or
-not.
 \end{itemize}
 
 \subsection*{Changes}
@@ -598,9 +595,6 @@ \subsection*{Changes}
 \item In \texttt{pspm\_get\_eyelink}, \texttt{import.flank} set to \texttt{'all'}.
 \item The test of \texttt{pspm\_extract\_segments} was adapted to the new
 feature.
-\item Suppress redundancy in \texttt{pspm\_compute\_visual\_angle}.
-\item \texttt{pspm\_bf\_spsrf\_box} and \texttt{pspm\_bf\_spsrf\_gamma}
-were adapted to the new feature in \texttt{pspm\_glm}.
 \item External functions and libraries were regrouped in one folder called
 \texttt{ext.}
 \end{itemize}