Renamed 'oversigt' (Danish) to 'dashboard'

(English), because this is an English-language code base. If the customer
insists on having Danish URLs, we'll figure out a way to alias those URLs.
Renamed 'oversigt' route to 'dashboard'.
Added a getNewTasks property on dashboard scope.

It should be a function, but further tests are needed to flush that out.
Made getNewTasks a function,

although it doesn't do anything yet.
Called Task Gateway from Dashboard Controller,

although the code currently ignores the return value and instead
hard-codes the values.
Assigned new tasks from gateway.
Added controllers.js to index.html.
Returned an object from the taskGateway factory.
Added a getNewTasks property to taskGateway,

although it's not yet a function.
Made getNewTasks a function.
Filled new tasks when creating dashboardController
Rewired dashboard template to dashboardController.
Deleted OpgaveListController,

because it was no longer needed. Functionality has been moved to
dashboardController.