Add context menus to some entries

Use ShellEntry.addContextMenu() to add context menus to most
existing entries, with the exception of:

 - the login dialog - it may act be used to enter either the
                      username (e.g. no password entry) or the
                      password, and copy/paste does not make sense
                      (nowhere to copy from, nowhere to paste to)
 - notifications    - while adding a context menu is useful here as
                      well, it will require changes to the tray's
                      focus grab handling, so leave those entries
                      out for now

https://bugzilla.gnome.org/show_bug.cgi?id=659275

js/ui/viewSelector.js

@@ -12,6 +12,7 @@ const St = imports.gi.St;
 const Main = imports.ui.main;
 const Search = imports.ui.search;
 const SearchDisplay = imports.ui.searchDisplay;
+const ShellEntry = imports.ui.shellEntry;
 const Tweener = imports.ui.tweener;
 
 function BaseTab(titleActor, pageActor, name, a11yIcon) {
@@ -120,6 +121,7 @@ SearchTab.prototype = {
                                      hint_text: _("Type to search..."),
                                      track_hover: true,
                                      can_focus: true });
+        ShellEntry.addContextMenu(this._entry);
         this._text = this._entry.clutter_text;
         this._text.connect('key-press-event', Lang.bind(this, this._onKeyPress));