python3: Fix staging warnings due to duplicate install

This fixes the warnings like

WARNING: The recipe python3 is trying to install files into a shared
area when those files already exist. Those files and their manifest
location are:

builds/world/tmp/sysroots/qemux86-64/usr/include/python3.3m/pyconfig.h
builds/world/tmp/sysroots/qemux86-64/usr/lib/libpython3.3m.so.1.0
builds/world/tmp/sysroots/qemux86-64/usr/lib/libpython3.3m.so
builds/world/tmp/sysroots/qemux86-64/usr/lib/python3.3/config/Makefile

Signed-off-by: Khem Raj <raj.khem@gmail.com>
python-setuptools: Remove its provided by python-distribute

Use python-distribute-native in packagegroup-toolset-native

Also fixes warnings like

WARNING: The recipe python-setuptools is trying to install files into a
shared area when those files already exist. Those files and their
manifest location are:

/srv/ssd/sgw/builds/world/tmp/sysroots/qemux86-64/usr/lib/python2.7/site-packages/setuptools.pth
    Matched in manifest-qemux86-64-python-distribute

/srv/ssd/sgw/builds/world/tmp/sysroots/qemux86-64/usr/lib/python2.7/site-packages/site.pyc
    Matched in manifest-qemux86-64-python-distribute

/srv/ssd/sgw/builds/world/tmp/sysroots/qemux86-64/usr/lib/python2.7/site-packages/site.py
    Matched in manifest-qemux86-64-python-distribute

Signed-off-by: Khem Raj <raj.khem@gmail.com>