Rename detla_ui.js to delta_ui.js

Following error message reported... typo in js file.

Error message
Warning: file_get_contents(sites/all/modules/contrib/delta/detla_ui.js) [function.file-get-contents]: failed to open stream: No such file or directory in drupal_build_js_cache() (line 4749 of /Users/himerus/Desktop/Dropbox/Development/www/himerus/includes/common.inc).

This JS is actually not used, and held-over from previous attempts to build the interface. Will rename, but leave file empty & intact, and some jQuery enhancements WILL be added back to this file.