Move utils to python -m vectortile

[geowurster]

There is no easy way to translate vectortile data unless you have the git repo at hand. We don't need to clutter everyone's path with utils like tile2tile.py, but they are useful to have accessible whenever the module is installed.

[redhog]

Why can't we have one click-based toplevel "vectortile" command that has subcommands for all needs?
Requiring the user to use a script in lib/python2.7/site-packages/vectortile with python -m sounds clumsy and non-standard to me...

[geowurster]

@redhog We can, but we use it so infrequently that python -m seems fine for now and we can always switch to an actual utility. python -m is a standard way to do this, for example: python3 -m venv is the new method for creating virtual environments now that virtualenv is part of the standard lib, and echo '{"key": "val"}' | python -m json.tool pretty prints JSON.