Implement profile page and modify templates.

Add: a profile page with necessary styling.

	templates/profile.html
		-profile page with user-specific information: currently displays
		username, a change password button, and the user's posts.

	__init__.py
		-route for profile page, with appropriate error message
Mod:
	utils.py
		-formatPosts() and getQuotes() are now called separately by a
		posts() function. getQuotes() and posts() intake an optional
		username argument, which specifies the user whose posts will be
		returned; no argument returns all posts. A clean modification to
		facilitating querying posts from specific users for the profile
		page.

	style.css
		-convert error messages from fixed-width (px) to relative-width
		(%) for greater screen portability.

	templates/home.html
		-is now extended by the profile page, which inserts appropriate
		headers (with a username and user-specific information) above
		the displayed posts. Also, add appropriate warning message for
		attempt to access profile without having logged in (no username
		in session).