initial add of scratch activecode modal
allow scrollbar in scratch activecode block
Merge pull request #214 from isaacdontjelindell/scratch-editor

Add "scratch" ActiveCode to search menu
Minor tweak to new scratch editor so that it starts with more than one line.
Add course_url to template hrefs for web2py generated pages

This further helps configure a course so that the static content could be hosted anywhere but the links to  web2py content will link back to a running web2py server.