Needed to delete bundle cache in ~/.igb directory

Issue is ready for first level review.

Link to the commit branch:
https://bitbucket.org/djoshi4/deepti-fork-igb/commits/285a33580e76521f7b162ca30617aa3afe2ed3eb

The issue has built on bitbucket pipelines and the jar is available in the downloads.

Ann added a comment on bitbucket, regarding line 398 "See line 387. Don't add this file extension if full_path ends with any of the allowed options, which include both JSON (upper case) and json (lowercase)"

I modified line 398, the program will not tack on ".json" if the file already ends in .json OR .JSON.

When testing this, I found that the system is misbehaving. See FileExtensionNotPermitted.png.
As long as I don't include any file extension, everything is fine.
If I DO include a file extension, even the ideal one: .json, the system gives me a dialogue box saying that this extension is not allowed, it must be "." ???
I think the issue lies in FileChooserUtil.java. The file chooser is creating this unwanted dialogue box.

I think the code in WebLinksView.java is behaving as expected. So this problem is outside the scope of this issue.
However, I don't think WebLinksView should handle the file extension at all. I think that should be handled by the file chooser. So lines 398-400 (below) should not be in here at all.

if ( ! (full_path.endsWith(".json") || full_path.endsWith(".JSON")) )

After talking to Ann, I decided the best solution for the newly found mis-behavior is to just remove the file extension filter from the file chooser.
That commit, and the one allowing for JSON (upper case) have been squashed into the original commit "Changed file chooser to local OS".

My testing confirms that this story is now resolved. When exporting on Mac and Windows, the Export option for "Configure Weblinks" is using the native file chooser. If I did not enter a file extension, .json was properly added, and if I did enter .json as the file extension, the file was saved properly with only a single .json extension. I tried to break this but could not, and there seem to be no side effects related to this change, so it will now be closed.