fintersect order

[ben-schwen]

Closes #4716 fintersect now preserves order of 1st argument like intersect does instead of preservering order of 2nd argument.

[codecov]

Codecov Report

Merging #4725 (17e0916) into master (dae9652) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #4725   +/-   ##
=======================================
  Coverage   99.47%   99.47%           
=======================================
  Files          73       73           
  Lines       14559    14559           
=======================================
  Hits        14482    14482           
  Misses         77       77           

Impacted Files	Coverage Δ
R/setops.R	100.00% <100.00%> (ø)

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[mattdowle]

Thanks, Ben and welcome! I've added your name to the contributors list in DESCRIPTION so you're now a copyright holder of data.table. I've also invited you to be a project member so that in future you can create branches in the main project. That makes it a bit easier to work on each others branches if they are in the main project rather than a fork. To accept the invitation there should now be a button in your GitHub profile or projects page that you have to click.