Update PointMass.h

Wilbert's changes
Update Vectors.h

Wilbert's Changes
Update physicsengine.h

Wilbert's Changes
Update physicsengine.h
Wilbert's Changes
Update: README.md

Add my name to the readme file
Merge pull request #1 from gunlockz/master

Update: README.md
Reinsert some functions
Vector Space
Vector Space
Vector Space
File Name Congruence
PE and I
Fixing incongruencies