Added drawLineVector and drawArrowVector

[ckiran2508]

Hi Keith,

I love watching your coding math videos, they give me intuitive understanding of classical physics. I was playing around with vectors, I thought a function that draws a vector with its magnitude and direction information will be very handy and a good way to visualize on how the vector behaves over a period of time in system. Request you to kindly take a look of the added functions in the Vector.js file in application1 folder, and please let me know if they are a good fit or not with your comments.

Thanks, Kiran From India