Small fixes

Hello! This pull request is for fixing few small problems that I had with this portlet with Plone 4.3.3

The script in the portlet's template had the "jq" instead of "$" for jquery. This prevented rotation of banners.

The second problem was that every banner was added two times creating duplicates of each banner to the portlet. I traced it to the bannersportlet.py's getBannerInfo() function that had the "results.append(info)" two times. I removed the outer and it resolved the problem. Is this a correct way to fix it?

The third commit is to only start the rotation of banners if there is more than one banner. This will allow to use the portlet as a single banner.

Regards,
Juha