pull up r19970 from trunk

pull up r19970 from trunk

 r19970@cathode-dark-space:  jaltman | 2007-09-24 14:49:58 -0400
 ticket: 5766

 Remove the broken optimization from UnicodeToANSI() that attempted
 in a stupid way to avoid to WideCharToMultiByte() call by testing
 to see if the second byte (not wchar) was NUL.  This test works
 for Latin1 but not for anything more interesting.  Always call
 WideCharToMultiByte().

 I commented out the use of WC_NO_BEST_FIT_CHARS in order to
 provide compatibility with Windows.  Windows converts the user
 name without that option.

 With the current code a principal name consisting of a single
 component equivalent to the Greek character Sigma and a realm
 name will be converted to S@REALM exactly as the "WhoAmI"
 command does.  If WC_NO_BEST_FIT_CHARS was specified, this
 string would be converted to "?@REALM".

ticket: 5766
version_fixed: 1.6.3

git-svn-id: svn://anonsvn.mit.edu/krb5/branches/krb5-1-6@20047 dc483132-0cff-0310-8789-dd5450dbe970