Adds the functionality to do HTTPS downloads behind proxies using an
HTTP CONNECT.
Removed some trailing spaces that I left.
Improved error handling.
Raises a custom TunnelError when the tunnel cannot be opened. Removed unnecesary comments.
Adds support for proxy authentication when openning a CONNECT tunnel.
Adds the option to omit the usage of a CONNECT tunnel by adding the noconnect
parameter to the URL of the proxy.
The response matching re is now compiled once at module load time.
Changed the proxy tests to use libmproxy instead of starting mitmdump as a separate process.