make the use of `curl <url> | sh` more secure

Hi,

after reading these nice articles on the danger of the use of curl <url> | sh :

- http://blog.classicalcode.com/2012/11/curl-pipe-sh-exploit-proof-of-concept/

- http://www.djm.org.uk/protect-yourself-from-non-obvious-dangers-curl-url-pipe-sh/

check by yourself : http://pipe-to-sh-poc.herokuapp.com/

I've written this handy script that is more user friendly in every day use : https://gist.github.com/eviweb/7882632

Eric