Responder displays resource on api controller#update.

Ember seems to expect to get an updated version
of the resource after updating it, or else the
resource will move in to isError state.
Small tweak to the human time length helper.
Editing tasks "in place" is working.

This is kind of fun: In the list.handlebars
we are rendering tasks/table. This renders
the template as expected and creates corresponding
view and controller in memory.

The TasksTableController is an array controller
which I configured with the "itemController" to
wrap each of it's item in to it's own
TaskTableRowController. This helps me keep state
on each row, like if we are editing that row or not.

The actions defined in table.handlebars is dispatched
to it's controller (TaskTableController). I did not
find any good way to send actions straight to the
TableRowController, so I am kinda delegating actions
to each TaskTableRow controller.

In the TaskTableRow controller I am setting up
transaction to make sure we can "roll back" if the
user clicks the Cancel button.
Disable delete-list button if tasks are dirty.

Well.. Don't think we _really_ need this, as a user
should be able to delete a list maybe even if all
tasks have not been completed. But: I am having
fun with ember and playing with it's computed
properties :-)
Wanna see router transitions in log? This is how :-)
Fixed variable names within listController.
Fixed Task Serializer, we now send list_id.

Active model serializer seems to serialize has_one
in a way Ember does not expect. It results in
list: 1, but I need list_id: 1.
It is now possible to delete tasks from a list.
Update README.md
Adding tasks work, but rolling back new-task-transaction fails :(
"Fix" for rolling back new-task-transaction rollback.

Without this, when I try to roll back the transaction created by the
tables controller when adding a new task will fail with:

Uncaught TypeError: Cannot call method 'hasOwnProperty' of undefined

application.js:44396
DS.JSONSerializer.DS.Serializer.extend.extractId application.js:44396
DS.Serializer.Ember.Object.extend.materialize application.js:43776
DS.Adapter.Ember.Object.extend.materialize application.js:45184
DS.Store.Ember.Object.extend.materializeData application.js:39085
DS.Model.Ember.Object.extend.materializeData application.js:41609
DS.Model.Ember.Object.extend.data application.js:41600
ComputedPropertyPrototype.get application.js:15395
get application.js:13807
getAttr application.js:41969
(anonymous function) application.js:41994
ComputedPropertyPrototype.get application.js:15395
get application.js:13807
Ember.Observable.Ember.Mixin.create.get application.js:21164
Todo.Task.DS.Model.extend.minutesLeftToComplete application.js:45926
ComputedPropertyPrototype.get application.js:15395
get application.js:13807
(anonymous function) application.js:19440
(anonymous function) application.js:19425
Ember.Enumerable.Ember.Mixin.create.forEach application.js:19360
Ember.Enumerable.Ember.Mixin.create.map application.js:19424
Ember.Enumerable.Ember.Mixin.create.mapProperty application.js:19439
Ember.Enumerable.Ember.Mixin.create.getEach application.js:19376
Todo.List.DS.Model.extend.minutesLeftToComplete application.js:45902
ComputedPropertyPrototype.get application.js:15395
get application.js:13807
Ember.ObjectProxy.Ember.Object.extend.unknownProperty
application.js:23395
get application.js:13817
Ember.Observable.Ember.Mixin.create.get application.js:21164
Todo.ListController.Ember.ObjectController.extend.isNotCompleted
application.js:45946
ComputedPropertyPrototype.get application.js:15395
get application.js:13807
Ember.Handlebars.get application.js:29466
observer application.js:30609
(anonymous function) application.js:16004
Ember.handleErrors application.js:12357
invoke application.js:16002
invokeOnceTimer application.js:16447
(anonymous function) application.js:16004
Ember.handleErrors application.js:12357
invoke application.js:16002
iter application.js:16074
RunLoop.flush application.js:16128
RunLoop.end application.js:16033
tryable application.js:16237
Ember.tryFinally application.js:12995
Ember.run.end application.js:16240
autorun
Bugfix in list model when calculating minutesLeftToComplete.

..must parseInt the min-value, as it is a string when it is set on a new
record from the form.