deepcopy is broken for SharedArrays

[carlobaldassi]

In particular, trying to assign elements from a different process silently fails.

julia> a
3x4 SharedArray{Float64,2}:
 -0.978909   0.956941  -0.727437   0.123889 
  1.52651   -0.524361  -0.69585   -0.0347904
  0.556024   1.01309    0.724335  -1.39348  

julia> b = deepcopy(a)
3x4 SharedArray{Float64,2}:
 -0.978909   0.956941  -0.727437   0.123889 
  1.52651   -0.524361  -0.69585   -0.0347904
  0.556024   1.01309    0.724335  -1.39348  

julia> remotecall_fetch(2, setindex!, b, 5, 4:6)
3x4 SharedArray{Float64,2}:
 -0.978909  5.0  -0.727437   0.123889 
  1.52651   5.0  -0.69585   -0.0347904
  0.556024  5.0   0.724335  -1.39348  

julia> b
3x4 SharedArray{Float64,2}:
 -0.978909   0.956941  -0.727437   0.123889 
  1.52651   -0.524361  -0.69585   -0.0347904
  0.556024   1.01309    0.724335  -1.39348  

[carlobaldassi]

Oh and worse than what is described above, the assignment acts on the original array:

julia> a
3x4 SharedArray{Float64,2}:
 -0.978909  5.0  -0.727437   0.123889 
  1.52651   5.0  -0.69585   -0.0347904
  0.556024  5.0   0.724335  -1.39348