New warnings with 0.4

[Viral B. Shah]

This warning happened after JuliaLang/julia#12739

               _
   _       _ _(_)_     |  A fresh approach to technical computing
  (_)     | (_) (_)    |  Documentation: http://docs.julialang.org
   _ _   _| |_  __ _   |  Type "?help" for help.
  | | | | | | |/ _` |  |
  | | |_| | | | (_| |  |  Version 0.4.0-dev+7032 (2015-08-27 04:01 UTC)
 _/ |\__'_|_|_|\__'_|  |  Commit 5d3ccd6 (0 days old master)
|__/                   |  x86_64-linux-gnu

julia> using HttpServer
WARNING: New definition
    write(#T<:Base.IO, HttpCommon.Response) at /home/sachs/.julia/v0.4/HttpServer/src/HttpServer.jl:178
is ambiguous with:
    write(#T<:Base.AbstractPipe, Any...) at stream.jl:547.
To fix, define
    write(#T<:Base.AbstractPipe, HttpCommon.Response)
before the new definition.
WARNING: New definition
    write(#T<:Base.IO, HttpCommon.Response) at /home/sachs/.julia/v0.4/HttpServer/src/HttpServer.jl:178
is ambiguous with:
    write(#T<:Base.DevNullStream, Any...) at process.jl:95.
To fix, define
    write(#T<:Base.DevNullStream, HttpCommon.Response)
before the new definition.

Cc: @vtjnash

[Jameson Nash]

that function (function write{T<:IO}(io::T, response::Response)) doesn't need to specialize on the type of io object, so it should be written more simply as function write(io::IO, response::Response).

i'm working on trying to fix this in Base also.

[Iain Dunning]

I followed @vtjnash's suggestion, seemed to fix it nicely