Added shell function for HEAD request.
Added shell function for HEAD request.

micha/resty,AdrieanKhisbe/resty,AdrieanKhisbe/resty,AdrieanKhisbe/resty,micha/resty,AdrieanKhisbe/resty,micha/resty,micha/resty,AdrieanKhisbe/resty,micha/resty