SciDAVis - Improvements SVN-temp

Improve import of TextNumeric data sets

From: Miquel Garriga <gbmiquel@...>

Do not import empty formulas

From: Miquel Garriga <gbmiquel@...>

Cosmetic changes in white space.

From: Miquel Garriga <gbmiquel@...>

Update of Czech translation

From: Pavel Fric <pavelfric@...>

lupdate translations

Fix needless QString to char* to QString conversion

This meant that table/column names with non-latin1 characters lead to corrupted
curve names when plotted.

Reported-by: Vit <vitruss@...>

Extend Russian translation

From: Vit <vitruss@...>

Fix bug #3109014 (mistake in Russian translation)

Reported-by: Anton Chehov <apcheh@...>

Document CurvesDialog::showCurveBtn(int)

From patch #3106338.
From: Dominik K. <dominik_k@...>

Fix disabling of "Edit function" button in CurvesDialog

The "Edit function" isn't disabled after deselecting it.

Steps to reproduce:
* have a curve plot and a function on a graph
* go there in the "Add/Remove Curve" dialog
* select the function
* select the table data
* click on "Edit function"
=> segmentation fault.

Patch #3106338 (minus a little buglet).
From: Dominik K. <dominik_k@...>