Automate import handling for the moved definition list

[lmmx]

After moving one or more funcdefs out of the file, I may want to then import them back in, and it'd be nice if this could be handled automatically (and since I'm already rewriting import statements it wouldn't be a big stretch)

• hello.py

def foo():
    print("foo")

foo()

• world.py

def bar():
    print("bar")

• mvdef -m foo hello.py world.py
• python hello.py should continue to print out "foo",
• hello.py should become:

from .world import foo

I'm not sure how you'd want to detect whether to use relative import (.world) or absolute package imports, but at least defaulting to relative would be simple and easily corrected...