fix endless "INFO: _hit_from_elem_imports:: ie: lookup ('',) in => []" i...

...n codeIntel for PHP

This is a fix for the issue described here:
http://community.activestate.com/node/10110#comment-26290
and here:
http://community.activestate.com/node/10419#comment-27216

When PHP-codeintel was doing a full scan on ALL possible imports without a lucky-hit (resulting in searching all files it has heard of, multiple times), this bug used to freeze the Application... on ... every ... keystroke!