Update XProfile admin area title CSS and JS to bring it up-to-speed with WordPress 4.0 expectations.

* Remove placeholder attributes on titles and rely on accompanying labels
* Show/hide title labels the way WordPress posts currently do
* Add 20px bottom margin to title wrappers to separate it from descriptions
* Tweak admin area form markup slightly to accommodate these improvements

git-svn-id: https://buddypress.svn.wordpress.org/trunk@9084 cdf35c40-ae34-48e0-9cc9-0c9da1808c22