Hide edit controls on changeset details page for unauthorized users

Created by: evilchewits

If a user has sufficient privileges at least in one project he is allowed to see "Attach", "Detach", and "Edit" buttons for any changeset on Details page (Source/view&id=<changeset_id>).

For example if Source plugin settings are: View Threshold: viewer, Update Threshold: developer And the user rights are: Global: viewer, Some project: developer

The user will see those buttons for any changeset (attached to any bug of any project, or not attached at all), if he change the current project to Some project in drop-down list.

This would look like a security issue, but these buttons do not actually work, because all actions are checked for global permissions afterwards.

This commit fixes the issue described above.