Live SDK 5.4 Changes

- Windows Store app: Ensure Live SDK for Store apps work with Windows
8.1 preview edition.
- Windows Store app: On Windows 8.1 preview, invoking
LiveAuthClient.LoginAsync from a local account will trigger a process to
connect the current user account with a Microsoft Account. If the user
account is disconnected from Microsoft account, calling methods on
LiveConnectClient class will fail.
- Windows Store app: Allow consent flow to happen if fail to retrieve
authentication token
- Windows Store app: Remove some deprecated properties from
LiveConnectSession class.
- Windows Phone 8: Fix the issue that re-login will reuse the web
session and not to prompt user to type in user credential.
- Windows Phone 8: Disable the caching for UploadAsync in order to avoid
running out of memory and fix inaccurate progress event data.
- Update version to be 5.4
- Fix Unix timestamp year 2038 issue in JsonWebTokenClaims.