Narrowing the distinction between ado-files and internal commands

• variable lists can now be as large as those used by internal commands
  
  
  • maximum macro length increased to hold longest possible varlist
    
  • 2,047 * 9 = 18,423 < 18,632
• double-quotes can be passed to ado-files
  
  

  logistic outcome x1 x2 if gender=="male"

• results are saved in the same form as internal commands
  
  
  • no more mix of _result(#) and $S_ macros
  • _result(#) is dead