Migrate issue/mr labels from act_as_taggable to own labels

app/finders/base_finder.rb

app/helpers/labels_helper.rb

app/models/concerns/issuable.rb

app/models/issue.rb

app/models/label.rb

app/models/merge_request.rb

app/models/project.rb

db/migrate/20140729152420_migrate_taggable_labels.rb

db/schema.rb

lib/gitlab/issues_labels.rb