Revisions to functions/functions2.rst

There are some commits about Assignments/* in this commit -- kinda had to deal to make my upsteam work -- the content should be the same as yours.

OF SPECIAL NOTE:

codelens function2_10 doesn't work. I'm not sure how to make the scoping problems you want to happen appear -- apparently python 2.7 isn't doing this (either in skulpt or my real interpreter)

also - skulpt doesn't implement the dict.copy() method (i ran into this in class thursday) --> calling dict() on a dictionary creates a new version though