VEC: Added space for Vector class definitions
VEC: Defined assignment operator for Vector class
COL: Pulled in Jeff's pull request for the Collision Engine

Discussed Iterator, Universe, and PointMass with Wilbert, Encourage simplification
e-mailed interested students in CS2 & talke to students in CS3A.

Signed-off-by: Eli Selkin <eselkin@go.pasadena.edu>