Windows8 platform fixes

Fixes the following issues:
CB-5321 Windows8 custom_path is not correctly resolved by CLI 
CB-5337 Windows8 build fails due to invalid app version 
CB-5340 Windows8 build does no write cordova_plugins.js 
CB-5350 Windows8 build fails due to invalid 'Capabilities' definition
CB-5400 - Version and Id is not set correctly in Windows 8 application project file
CB-5421 Add BOM to all html, js, css files to ensure app can pass Windows Store Certification