pull up r19488 from trunk

pull up r19488 from trunk

 r19488@cathode-dark-space:  jaltman | 2007-04-17 21:47:08 -0400
 ticket: new
 subject: kfwlogon corrections for XP
 component: windows
 tags: pullup

 This patch addresses a problem discovered on some XP systems.
 After rundll32.exe starts, the CreateProcess can fail to
 start kfwcpcc.exe if the current directory is not %WinDir%\System32.
 CreateProcess() should be called with the lpApplicationName parameter
 set to NULL in order to permit the use of the PATH.

 Also, in ConfigureLogonScript ensure that the trailing NUL of the
 constructed command line is processed when producing the wide
 character version of the string.

ticket: 5534
version_fixed: 1.6.1

git-svn-id: svn://anonsvn.mit.edu/krb5/branches/krb5-1-6@19491 dc483132-0cff-0310-8789-dd5450dbe970