Square bullet labels

* changes labelgroup.js to use squares instead of circles for bulleted/numbered/lettered labels
* bullets start on specified point, instead of having their centers on specified point
* updating some styling to match square bullets and new design in widgets.css
* update examples which use labels
Merge pull request #90 from ysahnpark/ClosureOOP_youngsuk

Closure-ify(still working): Barchart, Button, MultipleChoiceQ, MultiSele...
Merge pull request #91 from ysahnpark/ClosureOOP_youngsuk

Migrated MultipleChoiceQuestion and MultiSelectQuestion (including demo file and dependencies) to Closure
Cheap demo of zoom
* GlobalEnergyUse has a line in the handler to completely remove the graph, and draw a new one.  This is because we don't have redraw on axes.
* Added example to toc-structure.js
* also adding an example file that Chad made, but not in book.
Merge pull request #92 from ysahnpark/EventManagerEnhance

Event Manager and MessageBroker enhancements
Fix legend overwriting on redraw

fix missing y value for added white piechart wedge when given
data doesn't add to full pie.
also small fix to piechart update handler on kantorowski page
Merge branch 'upstream/LeslieDemoBranch'
Merge branch 'upstream/master'
added jquery 1.8 externs file and renamed the d3 externs file

The jquery 1.8 externs file came from
https://code.google.com/p/closure-compiler/source/browse/#git%2Fcontrib%2Fexterns
fix submitmanager, answerman, answermanpolling and fakeactivitydb closure conversion

removed most warnings.
Add some annotations to the d3 externs file

This has vastly reduced the number of warnings.
More annotations are still needed.
Added unsubscribe to IEventManager and a static dummyEventManager
Fix more compile warnings

improve d3 extern annotations
along w/ code in various brix
Fix more compile warnings and fix building jsdoc

improve d3 extern annotations
along w/ code in various brix
several files that jsdoc could not parse were fixed so that it could.
more d3 externs annotations to fix warnings
Add abstract base classes (ABCs) Bric, SvgBric and HtmlBric (w/ no initial functionality)
Extracted Axes class from widget-base and renamed it PrototypeAxes

This also moved the remaining compiler warnings from widget-base to the new widget-prototype-axes file.
Added SvgBric.draw as an abstract method

Mostly to see how it should be done.
@abstract is known to jsdoc3 but not to the closure compiler
Also jsdoc3 needed the function args specified which is why
SvgBric.prototype.draw is defined and immediately overwritten.
add base class to some brix

Also see the doc change for Image.draw.
jsdoc3 is not yet supporting @inheritDoc so I have
copied the doc from the base class so the documentation is more useful.
down to only 60 warnings from the compiler
barchart & labelgroup warnings are handled (added d3.transitionSelection annotations)

barchart has a valid warning that remains for Leslie.