Update name from Http to HttpServer and fix typos
`Http` is now `HttpServer`
Base.TcpServer -> Base.TCPServer
Added if for compatibility with pre-0.4's TcpServer.
Merge pull request #36 from astrieanna/fixTCPServer

Base.TcpServer -> Base.TCPServer
Merge pull request #35 from catawbasam/patch-3

`Http` is now `HttpServer`
Merge pull request #34 from catawbasam/patch-2

Update name from Http to HttpServer and fix typos