SciDAVis - Improvements SVN-temp

- Fixed leaving of PlotDialog on histogram page via OK without changes.
Closes bug #2804419.

provided corrections and update in Brazilian Portuguese translation

- fixed bug #2804454: Invalid cells are used in statistics on rows/columns
- fixed statistics update when columns are removed

- Fixed some issues with date/time plot axes. Partially solves bug #2802183.
Particularly, note that negative years naturally pop up when interpreting
small numbers as Julian dates; and that these are not supported by
the Qt::ISODate format. Thus, an explicit "YYYY-MM-DD" format should be
preferred.

- Made behaviour of cut and copy in Graphs more consistent. Closes bug #2797488.

- Fixed evaluation of col("name_with_underscores") with muParser.
Closes bug #2804435.

- Fixed recalculation of a subset of rows (deselected cells in the same column
were filled with zeroes).

- Made sure that error messages of column formulas are displayed only once (any
error condition during evaluation now aborts all further evaluations).
Closes bug #2795575.
- Fixed a memory leak in Table::recalculate(int,bool) (colscript was never
deleted).

- Implemented save/restore of the main window's geometry between sessions.
Closes feature request #1981334.

- Added sanity check to Graph::updateCurvesData(). If one of the columns of a
DataCurve changes type, remove the curve instead of crashing when trying to
update the axis format in DataCurve::loadData(). Closes bug #2802185.