title: How to make set of scripts available for all my Google Spreadsheets?
body: <p>Excel supports the concept of a PERSONAL.XLS file which contains my personal scripts, which I want to be able to use on any spreadsheet/workbook that I open.</p>
  
  <p>How do I do similar in Google Docs, i.e. have a set of scripts which, regardless of which Google Spreadsheet I open, will cause the onOpen event to be run and will thus add my extra menu?</p>