add some TODOs for getAssets
modify default gist viewer to http://pagist.github.io
remove show(T) as it has been made default.
initialize methods now use callSuper to set common fields.
bunch of significant changes.

- added srccode to hold source code
- allow template to be specified
- set static = T as default for show
- allow show to pass arguments to render
add a template for chart + code
modify default css in rNVD3.css
add create_chart to utils.R
bump up version