Make comparison function (gt, ge, ...) respect __array_priority__.
Revert "Make comparison function (gt, ge, ...) respect __array_priority__."

This reverts commit aa7a04741146c44ab1735782a89a60b038028bf2.
Commit from @seberg to make comparison use respect __array_priority__
Add test for the array_priority for comparison function.

Conflicts:
	numpy/core/tests/test_multiarray.py
reorder code to remove not needed computation in some cases.
fix comment style.
remove comparison not needed as this is check above and we break in that case.
Move computation inside an if to speed it up.
use assert function instead of python keyword
updated the comment.
code clean up. Remove code that was never executed.

@seberg saw this.
BUG: Class should inherit from object.
Merge pull request #3490 from cowlicks/backport-3324

Backport 3324