Update evaporate.js

Signature fails in case the file name has spaces. Using encodeURIComponent solves the problem.
Update README.md
Update README.md

https://github.com/TTLabs/EvaporateJS/issues/53
Update evaporate.js

Issue #58
Update evaporate.js

I tried to respect the original code indent pattern, but as I missed a '{' I preferred changing to the pattern I'm used to work.
Merge pull request #59 from fkjaekel/master

Update evaporate.js