added a way to set the current user. security implications: 0, because I don't have any perms.

modules/base/header.lua

@@ -101,6 +101,9 @@ do -- so local works
    return tT[pid].n,tT[pid].p,tT[pid].u
   end
  end
+ function os.setuser(user)
+  tT[cT].u = user
+ end
  function os.genenv()
   local et = {}
   setmetatable(et,{__index=_G})