Mark the circulators without direction indicator as deprecated e.g. with the given info below

The circulator without orientation is deprecated and you should use the new implementation with the given directions. This change was in the OpenMesh 4.0 changelog.

To not break existing code, we still have the old one in place. But it has some problems such as visiting entities twice when using the decrement operator.

If you use the ones with the direction specified, you are safe and get slightly better performance.