Revert "Optimistic locking for Issue and Merge Requests" The migration to add `lock_version` in !5146 to every issue and merge request takes too long on GitLab.com since it has to add a default value of 0 to every row. Unfortunately, Rails 4.2 doesn't work properly if the value is left as `nil`; anything using optimistic locking cannot be edited. This bug was fixed in Rails 5.0 via this commit: https://github.com/rails/rails/commit/13772bfa49325a8dc26410d2dcb555665a320f92. I suggest we revert this change for now, and when we upgrade to Rails 5.0 we can reintroduce this feature. See merge request !5245
Disable PostgreSQL statement timeout during migrations Long-running migrations may take more than the timeout allowed by the database. Disable the session's statement timeout to ensure migrations don't get killed prematurely. See merge request !5263
Fix issues last update timestamp not preserved after importing a project Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/19689 and https://gitlab.com/gitlab-org/gitlab-ce/issues/19792 (similar, but not the same) Now `updated_at` should be the time from the original project. See merge request !5253
Refresh branch cache after `git gc` As discussed in !5160, we should refresh the branch name list after expiring to make sure we are in a good state and that we do not affect view performance (as much). See merge request !5235
GL dropdowns in issuable form ## What does this MR do? Changed all the issuable dropdown menus over to user GL dropdowns. This brings the dropdowns to be inline with the issuable filter dropdowns and allows for labels to be created whilst creating/editing an issuable. ## What are the relevant issue numbers? Closes #12574 ## Screenshots (if relevant) See merge request !4970
Updated compare dropdowns ## What does this MR do? Removes jQuery autocomplete from compare fields and replaces with GitLabs dropdowns. ## What are the relevant issue numbers? Closes #18891 ## Screenshots (if relevant)  See merge request !4895
Fix import_data being saved as a result of an invalid import_url Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/19479 Seem that in all cases the `import_url` was an empty string. The `import_url` is now validated correctly and no longer creates the `import_data`even if it fails validation. <= Should cover cases 1, 3, and 4 of https://gitlab.com/gitlab-org/gitlab-ce/issues/19479#note_13005276 Also, it now rescues from all exceptions when importing from a URL, so we make sure the `import_status` is failed after that. Covers case 2 of https://gitlab.com/gitlab-org/gitlab-ce/issues/19479#note_13005276 See merge request !5206
This reverts commit c39356998b1850f3dc26fe0b987cb419c1d1afb4.