Implement simple table widget. The data is currently stored in the widget settings, but this should be connected to the data api as and when needed

Escaping single quotes in json embed tag is actually un-necessary (and breaks the data) since the single quotes are replaced with html entities.

Implement the chart widget, and include the flot library. Data is communicated from Django to the javascript code using html5 data attributes, emembed using a Django custom filter.

hid expects the 'dashboard' reverse url to point to the index page - so leave it that way. Added an initial dashboard called 'main' as that is execpted to exist, and tests require it.

ItemTransport clas --> transport.items module

Implement a dashboard infrastructure to allow us to register widget types, create dashboards, create instances of widget types with specific configuration and associate those with a given dashboard, at a given position. The dashboard infrastructure is moved out of hid and into it's own application as it is stand alone (the widgets may depend on hid specific logic, but the infrastructure doesn't).

Replace with ItemTransport object, which needs to be instantiated. I
think it can be reused between calls to its methods so there's no need
to create new ones all over the place, but that's what I have done so
far. I'm a bit uncertain about module level variables, and not
everything is contained in a class.