Support AbstractArray in relative_entropy and log_perspective

[odow]

Closes #694

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 98.21%. Comparing base (b1ea4aa) to head (0b538e0).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #695 +/- ## ======================================= Coverage 98.21% 98.21% ======================================= Files 87 87 Lines 5198 5204 +6 ======================================= + Hits 5105 5111 +6 Misses 93 93 ```

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