Bugfix #47: Disable AsyncZipFilter until jetty bug is fixed

Jetty Bug: https://bugs.eclipse.org/bugs/show_bug.cgi?id=435322
Bugfix: Avoid throwing Exception and displaying default error page

When the User navigates to the #/meta/gene view by default no Gene is selected.
This will cause an exception in the RestProviderController.getGEnomeStatsData
method which will lead to an Javascript Exception on the client side because
GeneViewer can't deal with it. Instead of throwing an Exception, the Exception will
be logged and an empty DataTable will sent back.

This closes #45
Bugfix: Properly display the search autocomplete in the #/meta/gene view

Set overflow:visible on the top layoutpanel in order to properly display the
autocomplete box of the gene search widget.