Change uuid to a string in all locations. (#973)

additionally, the call to repr is no longer required.

Author: bluesmoon

src/init.jl

@@ -4,7 +4,7 @@ import Random: seed!
 # don't alter the user-visible random state (issue #336)
 const IJulia_RNG = seed!(Random.MersenneTwister(0))
 import UUIDs
-uuid4() = repr(UUIDs.uuid4(IJulia_RNG))
+uuid4() = string(UUIDs.uuid4(IJulia_RNG))
 
 const orig_stdin  = Ref{IO}()
 const orig_stdout = Ref{IO}()

src/msg.jl

@@ -15,7 +15,7 @@ mutable struct Msg
     end
 end
 
-msg_header(m::Msg, msg_type::String) = Dict("msg_id" => string(uuid4()),
+msg_header(m::Msg, msg_type::String) = Dict("msg_id" => uuid4(),
                                             "username" => m.header["username"],
                                             "session" => m.header["session"],
                                             "date" => now(),