FAKE.Deploy switched to FCS

@forki Please review code changes.
I tried these changes on my machine, but to get them to work i need to manually escape path to script before evaluation... See on the picture below. 
![image](https://cloud.githubusercontent.com/assets/1197905/3869536/1334e28e-2096-11e4-834f-0f90757f4e99.png)
It looks really strange ( i did not commit this). How it works now? Did you do it somewhere?