b2 install python=2.7 python=3.3 fails

[pdimov]

... with

error: Name clash for '<pc:\boost-prefix\lib\cmake\boost_python-1.71.0>libboost_python-variant-shared.cmake'
error:
error: Tried to build the target twice, with property sets having
error: these incompatible properties:
error:
error:     -  <python>2.7
error:     -  <python>3.3
error:
error: Please make sure to have consistent requirements for these
error: properties everywhere in your project, especially for install
error: targets.

See boostorg/python#262.

[pdimov]

@swatanabe Can you please offer some advice on this one? I hardcode boostcpp.tag here: https://github.com/boostorg/boost_install/blob/develop/boost-install.jam#L314, but the boost_python and boost_numpy libraries use their own local python-tag, which takes the value of <python> into account. I could of course special-case these, but it might be more proper to somehow use the <tag> of the library, instead of hardcoding boostcpp.tag.

[pdimov]

Should be fixed in develop.