Add working(?) google oauth button/javascript.

Add:
	templates/layout.html
		-add html for google sign-in button

	static/js/google_oauth.js
		-add oauth javascript.
Style google button; add profile image.

Add:
	app.py, static/js/google_oauth.js
		-to load a user's Google profile image/other information on different
		pages, the profile object (returned on successful login) must be stored
		in the Flask session.
		-add "/googleoauth" route, purely to intake an ajax'd POST from the
		oauth routine with a user's profile JSON.

	templates/layout.html
		-load a user's Google profile image instead of the "Sign in with Google"
		button if they're already logged in.

	static/images/socMedIcos/googlePlusTransparent.png
		-the same as {path}/googlePlus.png, except with an alpha'd (transparent)
		background. Used to show parent div's background color, for on-hover
		color-change effects.