list: cleanup, include offset in DateAttempt

included UTC offset in minutes in DateAttempt, will be used shortly.
Also moved this stuff (ParsedDate, DateAttempt) to the common d.ts, and
the method for parsing from a string (now parseDateString) to common.
Also pre-emptively load the user cache when the admin page loads.

ts/modules/accounts.ts

@@ -7,8 +7,6 @@ import { SearchConfiguration, QueryType, SearchableItem, SearchableItemDataAttri
 import { HiddenInputField } from "./ui"
 import { PaginatedList } from "./list"
 
-// FIXME: Find and define a threshold after which searches are no longer performed on input (or just in general by the browser).
-
 declare var window: GlobalWindow;
 
 const USER_DEFAULT_SORT_FIELD      = "name";
@@ -976,9 +974,6 @@ export class accountsList extends PaginatedList {
         });
         this._populateNumbers();
         
-        // FIXME: Remove!
-        (window as any).acc = this;
-
         let searchConfig: SearchConfiguration = {
             filterArea: this._c.filterArea,
             sortingByButton: this._sortingByButton,