Upgrade lodash to v4 and lint more files (#8495)

* common: import lodash modules separately

* remove test/content from .eslintignore, fix with eslint --fix content/index

* lint test/content

* lint content/index except for lodash methods

* upgrade server/models

* upgrade server/middlewares and server/libs

* port server/controllers/top-level

* port server/controllers/api-v3

* port views and tests

* client old port lodash and _(, missing _.

* upgrade client-old

* port common/script (root level files only)

* port common/script/fns

* port common/libs

* port common/script/ops

* port common/script/content and common/script/libs/shops.js

* misc fixes

* misc fixes

* misc fixes

* more tests fixes

* fix payments test stubbing, down to 2 failing tests

* remove more instances of lodash wrapping

* fix bug where toObject does not clone object

* fix tests

* upgrade migration or add lodash 4 note

* update shrinkwrap

* fix linting

* upgrade eslint-config-habitrpg

* update shrinkwrap

* recompile shrinkwrap

migrations/api_v3/users.js

@@ -9,6 +9,12 @@
 // Run the script with --max-old-space-size=4096 to allow up to 4GB of RAM
 console.log('Starting migrations/api_v3/users.js.');
 
+// IMPORTANT NOTE: this migration was written when we were using version 3 of lodash.
+// We've now upgraded to lodash v4 but the code used in this migration has not been
+// adapted to work with it. Before this migration is used again any lodash method should
+// be checked for compatibility against the v4 changelog and changed if necessary.
+// https://github.com/lodash/lodash/wiki/Changelog#v400
+
 require('babel-register');
 require('babel-polyfill');