Discrepancy between python-tag definitions in Boost.Python and superproject

In Boost 1.67, Boost.Python uses its own definition of `python-tag` rule in `libs/python/Jamfile`. This rule produces library names like `libboost_python36-py36.so.1.67.0`, notice the 36 after `boost_python`. This is different from Boost 1.66 and from the similar rule defined in the superproject, in `boostcpp.jam`.

In particular, this results in different naming between Boost.Python and Boost.MPI Python binding libraries. I'm not sure why the duplicate Python version is needed, so this issue requests to port Boost.Python to the superproject definition of the rule.

Compare the python-tag rule in libs/python/Jamfile with the similar definition in boostcpp.jam, focusing on why the Boost.Python rule adds the duplicated Python version to library names. Port Boost.Python to the superproject definition so its names match the Boost.MPI Python binding libraries and the stated Boost 1.66 convention.

Escrito por el modelo de indexación a partir del texto del issue.