• Adds detection for required window and window.document before running lib
• If lib is loaded more than once, only assign window.RmpVast once
  -getAdTagUrl|getAdMediaUrl|getAdSystem|getAdContentType|getAdTitle|getAdDescription|getClickThroughUrl|getAdCompanions now return '' when not available
• getVolume return -1 when not available
• getAdPaused|getMute|getAdLinear|getAdExpanded|getAdSkippableState now return false instead of null when not available
• Sets ajaxTimeout: 5000 and creativeLoadTimeout: 8000 as updated default