Merge pull request #97 from dj4b1n/master

Addition for worker/scheduler customization (pull request #90): updated _run_task in worker.py to return status so that the status can be used (i.e. sent to scheduler) in the custom worker/scheduler as necessary
Modified index for running task section

Modified luigi.js

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 pending tasks - note this feature would be better with pagination on tasks
Merge pull request #102 from VisualDNA/1-task-list-squashed

Added list of running tasks to the task list of the UI.
Merge branch '1-scheduled-tasks' of git://github.com/VisualDNA/luigi into VisualDNA-1-scheduled-tasks

Conflicts:
	luigi/static/visualiser/index.html
	luigi/static/visualiser/js/luigi.js
	luigi/static/visualiser/js/visualiserApp.js
Switch RawConfigParser -> ConfigParser.

Unsure how to unit test, but I did test it locally.
Merge pull request #106 from jcrobak/config

Switch RawConfigParser -> ConfigParser.
Added an error message when searching for a task that doesn't exist
Made it so that the error button will only show if there was an error
Changed ordering of tasks in the task list to be most recently submitted first (within each grouped list of tasks)
Merge pull request #107 from VisualDNA/error_on_bad_search

Added an error message when searching for a task that doesn't exist
Merge pull request #108 from VisualDNA/display_both_buttons

Made it so that the error button will only show if there was an error on task list
Merge pull request #109 from VisualDNA/order_tasks_by_most_recent

Changed ordering of tasks in the task list to be most recently submitted...
List done tasks in visualizer

List done tasks in visualizer as well as upstream failed and failed.

Show "Dependency graph" button for done tasks

Show "Dependency graph" not "Show error trace" button for done tasks in
task list.
Merge pull request #111 from VisualDNA/list_done_tasks

List done tasks in visualizer
Add tooltips with parameters to dependency graph.

Display only task name on the dependency graph.
Merge pull request #115 from VisualDNA/tooltips_for_graph

Add tooltips with parameters to dependency graph.
Added WorkerSchedulerFactory to interface.py to make worker/scheduler customization more complete and easier to integrate