Fix AttributeError When Running in Windows with No Console

[danyeaw]

Fixes #216.

Running PyInstaller with the option to enable verbose imports was causing an AttributeError, because PyInstaller couldn't write to sys.stderr because it was set to None due to having no console. Although this change is pretty straightforward, it required changes to the PyInstaller bootloader which is written in C to get the Python traceback information to debug the issue.

This also fixes an issue introduced with #236 to add the locale directory as data when packaging the app.

PR Checklist

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PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Documentation content changes

What is the current behavior?

The packaged version of Gaphor launches in Windows with a console visible.

Issue Number: #216

What is the new behavior?

The console is removed.

Does this PR introduce a breaking change?

• Yes
• No

Other information