Preparation for removing the $username parameter from db_log()

(will be detected by authentication_get_username() instead)

scripts/postfixadmin-cli.php:
- define ("POSTFIXADMIN_CLI", 1) (we have no session running and need a
  way to tell authentication_get_username() that this is a CLI access)

functions.inc.php:
- authentication_get_username(): check for POSTFIXADMIN_CLI constant,
  return 'CLI' if set
  (hmmm, do we need a similar thing for XMLRPC?)
- db_log(): override $username parameter with authentication_get_username()
  (removing it from function parameters will be my next big commit)


git-svn-id: https://svn.code.sf.net/p/postfixadmin/code/trunk@965 a1433add-5e2c-0410-b055-b7f2511e0802

scripts/postfixadmin-cli.php

@@ -557,6 +557,7 @@ class PostfixAdmin {
 }
 
 
+define ("POSTFIXADMIN_CLI", 1);
 
 $dispatcher = new PostfixAdmin($argv);