groups/010.host_deps.group:python[23]_host:${PKG_URLS_GIT}: update subdir to build/sbpython[23].
groups/010.host_deps.group:python2_host:${PKG_SUBDIR}: set to Python-${PKG_PYTHON2_HOST_VERSION}.
groups/221.native_packages_dev.group:python[23]:${PKG_URLS_GIT}: update subdir to build/sbpython[23].
groups/221.native_packages_dev.group:python2:${PKG_SUBDIR}: set to Python-${PKG_PYTHON2_VERSION}.
patches/python2_host-2.7.15.local.patch: split from vars/python2_host.vars.
patches/python3_host-3.6.3.local.patch: split from vars/python3_host.vars.
vars/python[23]{_host,}.vars: deleted