Github issue integration with search features.

[Gormartsen]

Integrate github issues with backdropcms.org via githubapi module.

Next features are requested:

• [ ] project/projectname/issues - issues list
• [ ] project/projectname/issues/search - search for issue by filter (https://developer.github.com/v3/search/#search-issues)
• [ ] project/projectname/issues - form to submit new issue with AJAX search to show a list of already opened issues by typed text in form
• [ ] search/issues - page to search issue for all contrib projects and https://github.com/backdrop/backdrop-issues/issues
• [ ] block "Recent issues" to display latests updated issues per project on project page

[quicksketch]

This sounds great to me. This could be implemented as either part of Project GitHub or as a new separate submodule. We might also want a block for "Recent issues" or similar so that we could place it on the project page itself.

[Gormartsen]

I added "Recent issues" to task list. I am going to create submodule to separate functionality.