Modified directory structure to used Soomla from UnityScript code

I took the liberty to move the 'Soomla/Assets/Soomla/Scripts' folder and its content to 'Soomla/Assets/Soomla/Plugins/Soomla/Scripts' to prioritize the C# scripts compilation so the API can be used from UnityScript code. This doesn't change any existing functionality and maintains compatibility with any project using Soomla in it's current form.

This is something I did at work in order to reach the Soomla API from our UnityScript codebase, I repackaged Soomla internally and I thought that other developers might be interested by this slightly altered directory structure.