feat(build): make everything buildable on Windows

(+) detects static libcurl and setup flags
(+) httpverbs itself is static-only
fix(request): cast length to curl_off_t

This casting must not be omitted because curl options are set through
va_args, which only do promotions, not implicit conversions.  Code
without this cast behaves badly on 32bit platforms.
fix(test): disable response move test for now