Script-Code is now loaded and executed via $.getScript() and $.globalEval()

Script-Code is now loaded and executed via $.getScript() and $.globalEval()

The script now utilizes jQuery.getScript(url,callback) and
jQuery.globalEval(code) when loading or executing the code of the detected
script-tags, because these functions work around several issues in older
browsers like IE 8 and Co.

TODO:
 * The gloabal variable OA_output, in which the OpenX-scirpt spc places the
   fetched banner-codes, is not defined under IE8, when the callback is
   called after loading the script. Does the jQuery-function getScript()
   not wait for the script, like suggested by the function-name?