Refactored local storage factory

* removed internal implementation of parser for Angular.toJson and
fromJson methods
* renamed file from localFactory.js to angular-local-storage-factory.js
as the name is more specific to its intended usage.
* added has method for determining if a key is in use
* added external configuration option for cookieFallback and
useSessionStorage
* added in-memory storage fallback if the Storage API is unavailable and
cookies are disabled
* added option to use Session Storage instead of Local Storage
* removed use of jquery cookies in favor of angular cookie service
* updated documentation for above functionality changes and added
dependency information