SSL support
Rename proxy function to ssl_handshake, consistency with set_timeout etc.
Test for parse_uri with https URIs
Docs for SSL options
doc: improved the code examples in Synopsis

* added proper error handling code for request_uri(), request(), and
  set_keepalive() calls to help trouble-shooting.
* added the "resolver" directive for the example with domain names.
* removed line-trailing spaces.
Merge pull request #18 from agentzh/docs

doc: improved the code examples in Synopsis
Merge pull request #19 from hamishforbes/ssl-cosocket

HTTPS Support
Ensure keepalive flag is reset during connect for subsequent connections, plus tests. Should fix #21
Avoid bail when attempting to read the request body in a subrequest