try to reflect package structure in the generated python files
Move code into mypy package
move driver.py out of mypy dir
Fix running the generated python
Merge branch 'master' into package-support

Conflicts:
	mypy/cgen.py
	mypy/checkexpr.py
	mypy/icode.py
	mypy/nodes.py
	mypy/strconv.py
Merge branch 'master' into package-support

Conflicts:
	mypy/cgen.py
	mypy/checkexpr.py
	mypy/checkmember.py
	mypy/erasetype.py
	mypy/icode.py
	mypy/infer.py
	mypy/join.py
	mypy/meet.py
	mypy/messages.py
	mypy/nodes.py
	mypy/solve.py
Fix tests