WP8.1 universal app

This pull request adds Windows 8.1 Universal App Support.and cleans up the previous pull request to make it easier to review. 

Visual Studio 2013 Update 3 or higher is required to build the Universal App projects.

cocos-console needs to be updated to replace HelloCpp with the project name in the win8.1-universal cpp template.

Added basic text input

Added UIEditBox support for Windows 8.1 Universal App

Updated precompiled shaders for WP8

Fixed WP8 shader compiler