Replace hard-coded date formats with Django formats

[Thai Tran]

We are currently using hard coded date formats in various D3 charts. We have things like "%Y-%m-%dT%H:%M:%S" scattered throughout the code. We should really be using Django's date format. Here are a few of the formats available:

 django.formats = {
    "DATETIME_FORMAT": "N j, Y, P",
    "DATETIME_INPUT_FORMATS": [
      "%Y-%m-%d %H:%M:%S",
      "%Y-%m-%d %H:%M:%S.%f",
      "%Y-%m-%d %H:%M",
      "%Y-%m-%d",
      "%m/%d/%Y %H:%M:%S",
      "%m/%d/%Y %H:%M:%S.%f",
      "%m/%d/%Y %H:%M",
      "%m/%d/%Y",
      "%m/%d/%y %H:%M:%S",
      "%m/%d/%y %H:%M:%S.%f",
      "%m/%d/%y %H:%M",
      "%m/%d/%y"
    ]

As you can see, the hard-coded format is very similar to django.formats.DATE_TIME_INPUT_FORMATS[0]. Why do we wan to do this? Django handles internationalization for us, so it make sense to take advantage of this.

People in different locale read dates differently. For example,
In english: "%Y-%m-%d %H:%M:%S"
In spanish: "%d/%m/%Y %H:%M:%S"

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/116686

[OpenStack Infra (hudson-openstack)]

Change abandoned by Thai Tran (<email address hidden>) on branch: master
Review: https://review.openstack.org/116686