Update lowpro.js for Firefox 3.5 fix
Update lowpro.js for Firefox 3.5 fix

Merging changes from git://github.com/danwrong/low-pro as described at
http://www.danwebb.net/2009/7/2/low-pro-for-prototype-and-firefox-3-5

jfqd/radiant-ad_banners-extension,jfqd/radiant-ad_banners-extension,davec/radiant-ad_banners-extension,davec/radiant-ad_banners-extension,jfqd/radiant-ad_banners-extension