Add class to whats-new-form re-factor form var to use .closest - global/buddypress.js

[hnla]

This patch provides a class for the whats-new-form form on submission of new update via ajax.

A class added after submit and existing for the page view state after submit and before page re-fresh aids the developer in having a hook that represents the ajax action and allows styling based on this event.

Patch adds the class on submit & removes the class onfocus of the textarea.

Patch also clears up another instance of traversing the DOM tree using .parent().parent().parent() in favour of the less resource hungry and lighter object .closest() to find the submits parent form element - relates to older ticket:
​http://buddypress.trac.wordpress.org/ticket/3821#comment:16

These changes ought to be safe, class can be ignored and not effect established themes.

[hnla]

Adds/removes 'submitted' class to update form - removes use of .parent()

[DJPaul]

Patch needs refreshing to make the indentation consistent, and we'll put it in the next next release so we have time to double-check the javascript change.

[hnla]

revised refreshed patch for indents

[hnla]

Bumping this for inclusion into 1.8 milestone.

[boonebgorges]

In 7161:

Toggle 'submitted' class on whats-new-form when posting activity items

This new class will make nice styling effects easier to build into child
themes.

See #4816

Props hnla

[boonebgorges]

In 7162:

Use jQuery.closest() to find form when submitting activity update

Using closest() instead of traversing with parent() makes the JS much more
flexible, as theme authors are free to change how elements are nested without
breaking the JS.

Fixes #4816

Props hnla