Fix form/date_time helper
Improve ajax call to build composer page url slug

* Disable form submission until the ajax request has finished
* Don't do ajax request if page name is the same as the previous ajax
  request
* Take in account the ajax response (success of fail) only if it's for the
  last ajax request
Patch current Chosen with some code from 0.9.9

Let's add support for the these options:
# placeholder_text_multiple: defaults to "Select Some Options"
# placeholder_text_single: defaults to "Select an Option"

These options are the same of newer version of Chosen: if we'll upgrade
Chosen we won't have to patch it again.
Translate some strings for Chosen

Introduce a new ccmi18n_chosen JavaScript object that contains translated
strings for Chosen (it can be used as the option parameter when
instantiating Chosen).
Add a description to a translatable text
Localize Chosen in File manager
Localize Chosen in Search Users
Localize Chosen in Bulk Group Add
Localize Chosen in Bulk Group Remove
Unify form submission event handlers

Let's have just one function that handles the submission validation
Remove Unused Var FileAttributeKey::saveAttribute

Remove usused value from `FileAttributeKey::saveAttribute()`

`$v` is assigned an array but is not used in the next db query. It is
likely left over from an earlier change.
list attributes by AttributeSet display order
Fix loading attribute keys with $akIdentifier = false

If $akIdentifier is false, the query executed by AttributeKey->load()
returns random data, since a text column is checked agains 0
(see for instance http://sqlfiddle.com/#!2/38237/2)
Add ERROR as possible job status

If a job fails, its status is set to 'ERROR'. BTW that state is not
included in the list of available statuses ($availableJStatus).
Merge pull request #1599 from mlocati/fix-job-status

Add ERROR as possible job status
Merge branch 'attribute-display-order' of https://github.com/jordanlev/concrete5 into jordanlev-attribute-display-order
Merge branch 'master' of github.com:concrete5/concrete5
Merge pull request #1544 from mkly/remove_unused_array_value

Remove Unused Var FileAttributeKey::saveAttribute
Merge pull request #1395 from mlocati/fix-slug-ajax-build-composer

Improve ajax call to build composer page url slug
fixing area design issue