`using` loads modules on workers but does not put exported bindings in Main

This may be intended, but it seems a bit awkward to me:

$ julia -p 1
[...]
  | | |_| | | | (_| |  |  Version 0.4.0-dev+1922 (2014-12-02 23:10 UTC)
 _/ |\__'_|_|_|\__'_|  |  Commit e4e1688* (0 days old master)
|__/                   |  x86_64-apple-darwin14.0.0

julia> using StatsBase

julia> @everywhere assert(isa(StatsBase.sample, Function))

julia> @everywhere assert(isa(sample, Function))
exception on 2: ERROR: sample not defined
 in eval at /usr/local/julia/base/sysimg.jl:7
 in anonymous at multi.jl:1395
 in anonymous at multi.jl:820
 in run_work_thunk at multi.jl:593
 in run_work_thunk at multi.jl:602
 in anonymous at task.jl:6

Obviously the workaround is @everywhere using StatsBase, but I think that using X should probably be equivalent to @everywhere using X, or if not, it should act exclusively on the main process. Instead it seems we get using X on the main process and require("X") on the workers.

Reproduce the report with julia -p 1, using StatsBase, and the two @everywhere assertions. Start by tracing the using and worker-loading behavior in multi.jl, alongside the shown sysimg.jl path. Done should mean the chosen module-loading semantics are consistent and covered by a regression test.