Losslessly optimize images

Used pngcrusher, optipng, advpng, jpegoptim and gifsicle to
optimize all images in a lossless fashion.

https://gitorious.org/fmarier-misc-scripts/user-scripts/source/optimize_images
Merge pull request #557 from fmarier/optimize_images

Losslessly optimize images
call correct highlightNodes function, fixes #550

colourHighlightNodes is never added to the global object, so calling it that
way resulted in a "function undefined" error. I believe this was due to an
earlier PR comment where I recommended we not add it to global because it is
only ever used inside graph.js. This is probably a leftover line that wasn't
changed for that comment.
Merge pull request #559 from mozilla/fix/empty-graph-after-blocking

call correct highlightNodes function, fixes #550
Point Feedback link to an email alias instead of Google Docs (fix #501)
Merge pull request #548 from fmarier/issue501

Remove link to Feedback Google Docs (fix #501)
Reduce the priority of debugging messages going to the console

These messages are in the normal (non-error) path and add to the
cout/cerr noise.

By default, `cfx run` has its output level set to `info` which
excludes the debug messages. To change this, set the
`extensions.sdk.console.logLevel` pref to `debug` or `all`.

https://developer.mozilla.org/Add-ons/SDK/Tools/console#Logging_Levels