SciDAVis - Improvements SVN-temp

- Fixed off-by-one annoyance in drawing of resize handlers.
- Added macro to data type and format change of columns using the control tab.

- Fixed typo in German translation.

- Fixed bug #2822092 (plot vanishes after vertical resize).

- Fixed crash when switching between date/time-like data types. Closes bug #2822087.

- Changed Plot3DDialog to use QDoubleSpinBoxes for zoom/scale and increased the
allowable range to [0,1e15]. Previously, changing anything on the General tab
would mess up a 3D plot which used zoom values below 1% or above 10000%.
- Added blocking of update signals during opening of matrices for a considerable
performance improvement when opening matrices with depending plots.
- Fixed some ambiguous keyboard shortcuts in German translation.

- Added compile-time option for choosing to always use the compiled-in path to
the manual instead of the user-configured one. Useful if packagers also
include the manual and want to push a changed path to their users.
- Choosing the path to the manual after SciDAVis failed to open it now uses
chooseHelpFolder() instead of implementing a slightly different procedure for
doing the same thing.

- Fixed handling of comments in muParser expressions. Closes bug #2820913.

Improved handling of plot tools:
- Allow different graphs to have plot tools active at the same time, making
sure that the tool buttons are updated when switching windows.
- When the data picker tool is active, up/down arrow keys switch between
corresponding points of different curves if possible instead of switching
to the first data point. Useful when comparing curves with the same X values.

- Fixed importing a table via Python with fewer columns than the target.

- Fixed unintended re-ordering when plotting multiple columns at once.