[WIP] reexport ImageBinarization and HistogramThresholding

[johnnychen94]

We need to review and update both packages before we reexport them here

TODO: (there will be more as we proceeding this)

• HistogramThresholding
• ImageBinarization
  • dispatch binarize on HistogramThresholding.ThresholdAlgorithm

The compilation time contributed by them doesn't look good right now

# Version 1.6.0-DEV.497 (2020-07-20)

# before
julia> @time using Images
  3.687936 seconds (9.14 M allocations: 584.557 MiB, 4.90% gc time)

# after
julia> @time using Images
  4.420445 seconds (11.35 M allocations: 714.150 MiB, 4.69% gc time)

cc: @zygmuntszpak

[codecov]

Codecov Report

Merging #905 into master will increase coverage by 7.33%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #905      +/-   ##
==========================================
+ Coverage   77.30%   84.63%   +7.33%     
==========================================
  Files           8        9       +1     
  Lines         661      944     +283     
==========================================
+ Hits          511      799     +288     
+ Misses        150      145       -5     

Impacted Files	Coverage Δ
src/Images.jl	25.00% <ø> (+25.00%)	⬆️
src/compat.jl	50.00% <0.00%> (ø)
src/deprecations.jl	85.32% <0.00%> (+2.56%)	⬆️
src/algorithms.jl	85.04% <0.00%> (+6.88%)	⬆️
src/corner.jl	84.29% <0.00%> (+9.29%)	⬆️
src/edge.jl	82.48% <0.00%> (+15.11%)	⬆️
src/labeledarrays.jl	100.00% <0.00%> (+23.07%)	⬆️

---

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[timholy]

Closed by #1030