List done tasks in visualizer

List done tasks in visualizer as well as upstream failed and failed.
Modified index for running task section
Small fix to JS indentation
Show "Dependency graph" button for done tasks

Show "Dependency graph" not "Show error trace" button for done tasks in
task list.
Modified luigi.js
Render dependency graph in Firefox

Dependency graph currently renders in Chrome but not Firefox, seemingly
because the SVG viewbox is not being scaled to cover the graph. Set
viewBox, height, and preserveAspectRatio attributes on the SVG element
to show the dependency graphs in Firefox.
Merge remote-tracking branch 'visualdna-external/list_done_tasks' into visualdna_hackday_2013-06-19
Merge remote-tracking branch 'visualdna-external/render_dependency_graph_in_firefox' into visualdna_hackday_2013-06-19
Tasks search autocomplete widget
Implemented running tasks, but also implemented done tasks
Removed the done list, so now just has running list
Made it so dependency graph button shows instead of error button (would be nice to have both really for all tasks)
Added an error message when searching for a task that doesn't exist
Merge remote-tracking branch 'visualdna-external/feature/task_search_autocomplete' into visualdna_hackday_2013-06-19
Added task status legend to visualiser
Merge remote-tracking branch 'visualdna-external/1-task-list' into visualdna_hackday_2013-06-19

Conflicts:
	luigi/static/visualiser/index.html
	luigi/static/visualiser/js/visualiserApp.js
Merge remote-tracking branch 'visualdna-external/error_on_bad_search' into visualdna_hackday_2013-06-19
Merge pull request #2 from VisualDNA/legend-for-task-status

Added task status legend to visualiser
Added pending tasks - note this feature would be better with pagination on tasks
Set minimum height of svg element based on legend height required