Project import functionality

This is a MR for the import functionality of https://gitlab.com/gitlab-org/gitlab-ce/issues/3050, which adds the ability to import single projects.

Branched off https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/3114

• members
• DB data
  • issues
  • issue comments
  • merge requests
  • merge request diff
  • merge request comments
  • labels
  • milestones
  • snippets
  • releases
  • events
  • commit statuses
  • CI builds
• File system data
  • Git repository
  • wiki
  • uploads
  • CI build traces
  • CI build artifacts
  • LFS objects
• DB configuration
  • services
  • web hooks
  • protected branches
  • deploy keys
  • CI variables
  • CI triggers

app/services/projects/import_export.rb

@@ -7,7 +7,7 @@ module Projects
     end
     def project_atts
-      %i(id name path description issues_enabled wall_enabled merge_requests_enabled wiki_enabled snippets_enabled visibility_level archived)
+      %i(project_members name path description issues_enabled wall_enabled merge_requests_enabled wiki_enabled snippets_enabled visibility_level archived)
     end
     def project_tree