HTTP Client
    The class http.Client implements a basic HTTP client. It is intended to encapsulate
    state that is persistent across connections, such as cookies and persistent connections. None of
    this functionality is, however, implemented currently.
    The http.Client class contains the following members:
    The library also provides a protocol, http.HttpProtocol that allows representing HTTP
    and HTTPS URLs. The library also provides convenience methods for creating the protocol:
- 
        http.QueryUrl httpUrl(core.Str host)Create HTTP urls conveniently. 
- 
        http.QueryUrl httpsUrl(core.Str host)
    To store query parameters, the library also extends the core.io.Url class with
    http.QueryUrl. It behaves as the core.io.Url class but also stores query
    parameters in its parameters member. It also allows adding parameters using the & operator as
    shown below.
For example, this allows fetching data through HTTP as follows:
Url url = httpsUrl("storm-lang.org") / "index.html" & QueryParam("id", "12"); print(url.toS); // Prints: https://storm-lang.org/index.html?id=12 Str data = url.readAllText(); print(data); // Prints the raw HTML.
    Note that all path components are escaped properly internally. Printing Urls with toS does not
    print them properly escaped. Using the format member will however give the escaped representation
    if you need it for something.
