SciDAVis - Improvements SVN-temp

- prepared release 0.2.1

- fixed bug #2672407: plot designation stuck after moving column

- right-clicking header of non-selected column selects it before displaying
the context menu

- fixed some issues with loading legacy project files

- Added automatic numeric format to matrix control tab.
- Ran all translations through lupdate (bug #2629682).
- Updated German translation.

- Added support for automatic numeric format ('g'/'G') and made it the default
choice. Looks much cleaner for many simple calculation, particularly when
dealing with integers.

- Fixed drawing of error bars in log scale which are larger than the value
(i.e., one end of the bar has negative coordinate). Closes bug #2658355.
- Fixed drawing of error bars for inverted scales.

- Implemented importing of ASCII files as numeric columns. Closes bug #2653763.
In contrast to SciDAVis 0.1.x, global decimal separator preference is never
used for this (i.e, "use custom decimal separator" is always assumed); and
the default locale used for ASCII import is "C". Rationale: Most applications
and programming languages use "C" conventions for dumping numbers, not
localized strings.
- Added "numeric data" option in place of "use custom decimal separator".
By default, this option is disabled, giving the same behaviour as in
SciDAVis 0.2.0 (so you get a faithful replica of the file, even if it
contains text or date/time data). By enabling it, you get the same
behaviour as in SciDAVis 0.1.x, which is useful if you're working with lots
of numeric data (assumed to be a common use case).

- optimized opening of 0.1.x projects with large tables
(related to bug #2664802)

- fixed bug #2657871: Functions and fits don't generate values in worksheets