adapting to coffee-script@1.6.2 'patch' and removing ability to set sourceFileRoot

adapting to coffee-script@1.6.2 'patch' 
- coffee-script takes care of the source inlining if this option is set
- a property was renamed as well which broke the tests - that is fixed

removing ability to set sourceFileRoot
- [mold-source-map](https://github.com/thlorenz/mold-source-map) allows doing this in a much more generic and powerful way
- therefore this feature is no longer needed