PR: Make "Are you sure you want to restart the kernel?" warning optional

[estraiton]

Pull Request Checklist

• Read and followed this repo's Contributing Guidelines
• Based your PR on the latest version of the correct branch (master or 3.x)
• Followed PEP8 for code style
• Ensured your pull request hasn't eliminated unrelated blank lines/spaces,
  modified the spyder/defaults directory, or added new icons/assets
• Wrote at least one-line docstrings for any new functions
• Added at least one unit test covering the changes, if at all possible
• Described your changes and the motivation for them below
• Noted what issue(s) this pull request resolves, creating one if needed
• Included a screenshot, if this PR makes any visible changes to the UI

Description of Changes

There is now an option to not show the dialogue box when restarting the ipython kernel. This will be less annoying for users who may wish to do this often.

Issue(s) Resolved

Fixes #7561

[pep8speaks]

Hello @estraiton! Thanks for updating the PR.

Cheers ! There are no PEP8 issues in this Pull Request. 🍻

Comment last updated on August 15, 2018 at 10:02 Hours UTC

[ccordoba12]

This is really nice @estraiton!! Great job for your first-time contribution to Spyder!

Thanks a lot for it!