Eigen expressions#23

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t4c1 wants to merge 4 commits intostan-dev:masterfrom

bstatcomp:eigen_expressions

Commits on May 22, 2020

Commits on May 25, 2020

added description of issues with local variables and returning expressions
t4c1
committed

Commits on Aug 5, 2020

updated info on tests
t4c1
committed