initialize repo with code from mutation-summary

Copied from https://code.google.com/p/mutation-summary/ repo. The
server and the extension share the same directory, in the original. Ex:
/examples/screen_sharing_extension
add the mutation summary and tree mirror libraries

Ex: read the actual README
mirror the active tab, all the time
extension should be persistant

http://developer.chrome.com/extensions/event_pages.html
extension should request the mirror server info

The mirror server might have diffent subdomain each time. The extension
should request mirror server info, from a localhost server (on port
17171) started by the devmirror client.
syntax fixes
should show remote-devtools, and mirrored page

index.html has two iframes, one linking to the remote-devtools served
via gotunnel. And the other linking to the mirror of users active tab.
server should support multiple projectors

Server should support serving multiple projectors at the same time. The
projectors are identified based on the subdomain of the host.

Change includes a somewhat better way to read files for serving.