PageRelated: fix empty page title
fix missing querying interface
minor fix

* update description
* rename parameter name
ListEx: convert second in |formatLabel|
ListEx: remove favicon of extension

* it is little merit to indicate file extension
* match favicons with the default history
ListEx: refactor a bit

* fix the shorten naming, |sh| to |sessionHistory|
* create convenient variables, |currentIndex|, |direction|
* remove useless initializing, |action|
* add @see comments
ListEx: update some comments
Util: implement |asyncScanPlacesDB| function
ListEx: refactor |buildTabHistory|

* get the visited time and favicon of a item with querying the places DB
  asynchronously
ListEx: refactor |buildRecentHistory|

* retrieve the recent history with querying the places DB asynchronously
* rearrange the menu building, using |insertBefore|
* delete the async function of |getFavicon|. it is useless no more