Specify module dependencies.

While dc.js has code to make it usable as CommonJS module,
it does not require its dependencies, so when using browserify,
both d3 and crossfilter still has to be present as window globals.

This patch adds necessary require call, and the code using dc.js
can now be bundled into a single js file.
propagate transition duration to d3.behavior.zoom object

d3 3.5 introduces smooth transitions for double-click zooming

this broke some tests, and it seems like (unless someone requests
otherwise) the transition duration should be controlled by the chart's
transitionDuration

so this is partly just to disable those transitions for tests, but also
because it seems consistent
grow bars upward

fixes #711
closes #759
closes #788

@r4j4h, we do need to take the margin into account here
@sergio91, I think yAxisHeight is clearer here, also no need for a function

Thank you both for your fixes!
artifacts from updated documentation tools
more doc artifacts
will the doc artifact churn never end?
more churn
Merge pull request #773
update version

for module dependency fixes in #773
artifacts; update stock fixture
Merge commit 'fdb6addca3bd7de1ab36dee447e5ed48bbb12fd4'