removed piechart.js

It seemed to be an unmodified old version of barchart. I suspect it was supposed to be morphed into piechart, but those changes got interrupted and never happened, and it got checked in anyway.
I removed it because jsdoc couldn't process it, and it wasn't useful in any way.
some minor changes to allow messagebroker.js to be processed by jsdoc
added comments on what the script does, made it more generic.
Added @export where needed to carousel and imageviewer
ImageTests.html works w/ uncompiled closure-ified sources (requires closure-library)

edit some annotations(comments)
add some goog.require statements
fix missing namespaces on classes
added the compiled brixlib built by build.sh and commented out the individual scripts

Image tests work using the compiled file instead of all of the uncompiled files.
The map file is NOT working at this time, so debugging the compiled source using the uncompiled source is not working (at least in the chrome inspector. I believe it has to do with the path to the files during compilation.