Update progress of milestones when closing/reopening issues and allow closing of issues in commit messages
Update closed issues stats for repository
Add delete route for attachments, remove upload buttons from issues/comments
Update template and style, only close commit if commit is in same repository
Merge pull request #305 from nuss-justin/feature/commit-issue-fix

Fix #302. Show referencing commits in issue.
Merge branch 'dev' into feature/attachments

Conflicts:
	models/issue.go
	routers/repo/issue.go
Fix missing . (dot) in issue templates
Allow admins to delete attachments.
Add files/ directory to .gitignore
Show attachments in issues/comments and add preview for images
Add file upload for attachments