Apply xface modifications to cordova.js

1. rename cordova.js to xface.js
2. added private module for xface
3. define xFace in order to invoke method 'getOriginalHandlers'
Update the logic of findCordovaPath for iOS
Added 'workspace' js module, which will be used by file plugin

1. Added 'workspace' js module, which will be used by file plugin
2. Refactored 'privateModule', added 'onPrivateDataReady' event which
indicates xFace private data
is ready.
3. Added unit tests for 'workspace' js module
Updated workspace js module, added support for absolute path

1. Updated workspace js module, added support for absolute path
2. Added corresponding unit tests.
Changed the return value type of checkWorkspace from boolean to string

1. Changed the return value type of checkWorkspace from boolean to
string
2. In order to reduce duplicate work, added platform-related code in
workspace js module
3. Added buildPath method in workspace js module
4. Updated the corresponding unit tests
Added one TODO comment in workspace js module, consider the situation of using TEMPORARY
[doing 184]fixe workspace.js check path error on wp8