SciDAVis - Improvements SVN-temp

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@...>

Re-activate builtin Origin OPJ import using liborigin2.

Patch by Miquel Garriga merged from import_origin branch.

The feature is disabled by default in order to avoid complicating the build
process and because it's (in its current form) not tested thoroughly.
Nevertheless, including it as an option in the next release will give it some
more exposure (and certainly isn't a regression).

Fix building with DOWNLOAD_LINKS enabled

Removes some remnants of translation download links missed in r1341.

Fix syntax error introduced by last commit.

Fix conversion of string columns to date/time

Fixes some of the issues discussed in bug #3072669.

Small improvements to opj2sciprj.

* handle canceling the input file dialog
* try to close SciDAVis after import

Import matrices and dump other objects into Note windows (from patch #2990795)

Import folder structure (from patch #2990795)

Try harder to find opjparse module (from patch #2990795)