Merge remote-tracking branch 'public/project-find-with-namespace-performance'

CHANGELOG

app/models/concerns/case_sensitivity.rb

app/models/project.rb

.../20151007120511_namespaces_projects_path_lower_indexes.rb

db/schema.rb

lib/gitlab/database.rb

lib/tasks/gitlab/setup.rake

lib/tasks/migrate/setup_postgresql.rake

spec/benchmarks/models/project_spec.rb

spec/lib/gitlab/database_spec.rb

spec/models/concerns/case_sensitivity_spec.rb