support cygwin with sbcl 

This patch enable to support  Cygwin & sbcl .

* add manipulate $OSTYPE code to shly
* change asdf:run-shell-command to uiop:run-program

thank you.
**[MAY]**
I'd like to avoid the common code between `uiop:run-program` part and `asdf:run-shell-command` part.
How about just adding `:uiop` to `:depends-on` if the environment uses ASDF2.
How do you think?