Nodezator

Among the many changes/additions for this patch release, we have:

- code contributed by Mr. sefgit via pull request, that consists of:
- mousewheel pan feature
- the addition of a .gitattributes file
- code contributed by me (KennedyRichard):
- the ability to confirm/dismiss/navigate the dialog using the keyboard
- a bug fix for a dialog that was growing past the screen


The mousewheel pan feature is the ability to pan/move the graph with the mousewheel. The .gitattributes file added is a simple text file that is used to define attributes to paths. Certain operations by Git can be influenced by assigning particular attributes to paths, which is what this file is used for. Some additional changes already discussed with the contributor were also made by me.

I also added/set the ability to confirm/dismiss dialogs with the keyboard using the **Enter** and **Escape** keys, respectively (though, often, confirming will also dismiss the dialog when it is the only action available). I use the terms "added/set" because part of the feature was already implemented and just needed to be properly set in the existing dialogs defined throughout the source. Naturally, some dialogs may not offer the option to be so casually dismissed like that when the consequences of the action cannot be reversed. Currently, though, we don't have any dialog like that.

The user can now also navigate the available dialog buttons/options using **arrow keys** or the **Tab** and **Shift+Tab** keys.

The bug fix consisted in preventing a specific dialog from growing past the screen.

In this specific bug, we were allowing text from error reports to be displayed on the dialog. The right practice, however, would be to just use known predefined text and record the error report in a more appropriate place for the user to check. Text from error reports can grow a lot when there are too many errors, so we must not use such text in dialogs. That's what was causing the problem.

Now, instead of reporting the error(s) on the dialog, we just display an informative small message and log the errors in both the default logger and our custom user logger. This way the user can check the error report using the log files or the user log that can be accessed on the app's GUI. The user log can be accessed by pressing **Ctrl+Shift+j** when you are on the graph/canvas or by selecting the **Help > Show user log** option on the menubar.

New unit tests for the function used to load nodes were provided by Mr. BMaxV via pull request. I KennedyRichard also refactored and complemented them.

I also used the opportunity to make some small improvements in the doctests and to fix one of them.

In order to make it more convenient to store test data, **.zip** files found in Nodezator's source are now also included in the source distribution. That is, they are downloaded in conjunction with the Python modules when someone installs Nodezator.

The bug in SVG exporting was fixed by removing unused code. The unused code was causing a name error because it was made from repurposed pre-existing code and was trying to access a variable that didn't exist in the new spot. Since HTML exporting relies on SVG exporting, HTML exporting was also being affected.

Some other lines that weren't causing errors but were not needed either were also removed to avoid confusion and needless maintenance.

The other bug fixed is related to change checking, that is, checking whether a change in a widget's value took place. Change checking was causing errors due to missing type checks. Such type checks were missing in different modules in the source and are now implemented.

More specifically, when a number changed, if the value was the same, even though the type was different, that change wasn't being treated properly, because the app was only checking the value and reaching the conclusion that nothing changed, because the value was the same in the end. However, this is not the right thing to do. That is, we must also take the type into account, because numeric values may have the same value and still have different types.

For instance, `0`, `0.0` and `0j` all have the same value, although they are an integer, a float and a complex number respectively. Because of that, wherever a value was being checked to determine whether a change took place, we also added a type check so this kind of change is also taken into account.

The error was caused by using the wrong attribute when retrieving the existing sockets from an operation node. Using the correct attribute name, by including an if/else clause that picked the appropriate attribute when needed, fixed the error.

The error was causing execution of the graph to fail altogether whenever operation nodes were present.

The error was caused by using the wrong attribute when retrieving the existing sockets from a collapsed node. Using the correct attribute name fixed the error.

The error was causing the output of collapsed nodes to be handled in the wrong way because it wasn't able to accurately determine the number of existing output sockets. This problem could cause all sorts of other problems, like the graph failing to execute or the wrong data being passed along to other nodes.

This tiny fix consists of the addition of a missing empty `__init__.py` file for packaging purposes. The absence of this file was causing some modules to be ommited in the pip installation, making the app crash on launch due to the missing modules.