admin: tab system improvement, search: ?search qp

tab content classes (e.g. settingsList, activityList)
can implement "AsTab", "Navigatable" and or "PageEventBindable",
the first giving them a tab name, a subpath and a reloader function,
the second an "isURL" and "navigate" function for loading resources,
the last giving them bind/unbindPageEvent methods. These are looped
through in ts/admin.ts still crudely, maybe tabs.ts could accept "AsTab"
implementers directly.

"Search" class now has a ?search query param which just encodes the
search box content, set when you perform a server search (hit enter or
press the button). ?user queries from the accounts or activity tab will
be converted to this form on loading.

ts/typings/d.ts

@@ -61,13 +61,28 @@ declare interface GlobalWindow extends Window {
     loginAppearance: string;
 }
 
-declare interface InviteList {
+declare interface PageEventBindable {
+    bindPageEvents(): void;
+    unbindPageEvents(): void;
+}
+
+declare interface AsTab {
+    readonly tabName: string;
+    readonly pagePath: string;
+    reload(callback: () => void): void;
+}
+
+declare interface Navigatable {
+    // isURL will return whether the given url (or the current page url if not passed) is a valid link to some resource(s) in the class.
+    isURL(url?: string): boolean;
+    // navigate will load and focus the resource(s) in the class referenced by the given url (or current page url if not passed).
+    navigate(url?: string): void;
+}
+declare interface InviteList extends Navigatable, AsTab {
     empty: boolean;
     invites: { [code: string]: Invite };
     add: (invite: Invite) => void;
     reload: (callback?: () => void) => void;
-    isInviteURL: () => boolean;
-    loadInviteURL: () => void;
 }
 
 declare interface Invite {