Added shortcuts

• Added:
- shortcuts functionality
- shortcuts route, controller, model
- shortcut error message for "exists"
- shortcut redux
- EditShortcutsModal, constant
- links to sidebar, sidebar_xs
- options to add/remove group, account in GroupOptionsPopover, ProfileOptionsPopover
- shortcuts page, feature/list

app/javascript/gabsocial/reducers/index.js

@@ -30,6 +30,7 @@ import reports from './reports'
 import search from './search'
 import settings from './settings'
 import shop from './shop'
+import shortcuts from './shortcuts'
 import sidebar from './sidebar'
 import statuses from './statuses'
 import status_lists from './status_lists'
@@ -72,6 +73,7 @@ const reducers = {
   search,
   settings,
   shop,
+  shortcuts,
   sidebar,
   statuses,
   status_lists,