Added urls patterns to log(in,out) and a template for the login page

Modified base.html template

Added new views

	modified:   PCnstein/urls.py
	modified:   PCnsteinapp/datautils.py
	modified:   PCnsteinapp/globdata.py
	modified:   PCnsteinapp/templates/base.html
	new file:   PCnsteinapp/templates/registration/login.html
	modified:   PCnsteinapp/views.py
	modified:   static/css/gen.css