Medic improvenents

config.json:
• Merged config.json.sample-windows and config.json.sample files

Windows:
• Added support of --nobuild key
• Creating mobile-spec application via createmobilespec script instead of custom code
• Fixed: Running grunt in cordova-js folder failed
• Fixed error with "COHO Clone failed: Invalid repo value: wp8
• Refactoring

Other improvements:
• Adding platform from downloaded folder instead of npm package