Codraft

Bug fixes:

* Improved support for LMJ-formatted HDF5 files.

* Z-axis logscale feature: freeing memory when mode is off.

* CodraFTMainWindow.get_instance: create instance if it doesn't already exist.

* to_codraft: show CodraFT main window on top, if not already visible.

* Patch/guiqwt.histogram: removing histogram curve (if necessary)
when image item has been removed.

New features:

* Image computations: added "Smallest enclosing circle center" computation.
* Added support for FXD image file type.

Bug fixes:

* Fixed image levels "Log scale" feature for Python 3 compatibility.

New features:

* Added "Delete all" entry to "Edit" menu: this removes all objects (signals or
images) from current view.

* Added an option "hide_on_close" to CodraFTMainWindow class constructor
(default value is False): when set to True, CodraFT main window will simply
hide when "Close" button is clicked, which is the expected behavior when
embedding CodraFT in another application.

Bug fixes:

* The memory leak fix in app.py was accidentally commented before commit.

Bug fixes:

* When quitting CodraFT, objects were not deleted: this was causing a memory
leak when embedding CodraFT in another Qt window.

* When canceling HDF5 import dialog box after selecting at least one signal or
image, the progress bar was shown even if no data was being imported.

* When closing HDF5 import dialog box, preview signal/image widgets were not
deleted, hence causing another memory leak.

New features:

* Added support for uint32 images (converting to int32 data)

* Added "Z-axis logarithmic scale" feature for image items (check out the new
entries in standard image toolbar and context menu)

* Added "HDF5 I/O Toolbar" to avoid a frequently reported user confusion
between HDF5 I/O icons and Signal/Image specific I/O icons (i.e. open and
save actions)

* Cross-section panels are now configured to show only cross-section curves
associated to the currently selected image (instead of showing all curves,
including those associated to hidden images)

* Image subtraction: now handling integer underflow

Bug fixes:

* When "Clean up data view" option was enabled, image histogram was not updated
properly when changing image selection (histogram was the sum of all images
histograms).

* Changed default image levels histogram "eliminate outliers" value: .1% instead
of 2% to avoid display bug for noise background images for example (i.e.
images with high contrast and very narrow histogram levels)

Bug fixes:

* When the X/Y Cross Section widget is embedded into a main window other than
CodraFT's, clicking on the "Process signal" button will send the signal to
CodraFT's signal panel for further processing, as expected.