python3: fixup python-package.mk include

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>
python3: avoid making python3 the default python command

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>
python3: enforce version assignment

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>
python3: include python*-package.mk irespective of DUMP env var

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>
python3: suffix vars with 3
python3: add python3 symlink to python exec as per PEP394
python3: fix python host path
Merge pull request #431 from commodo/python3-fix

Python3 fix