On svn-auth-x509 branch, hopefully fix the encoding problem on Windows when
iconv is unavailable.

* subversion/libsvn_subr/x509parse.c
  (x509name_to_utf8_string): Use the IANA character set names that should be
    compatible with the Windows built in character set APIs.  Previously this
    had the names that iconv expected.  But, this appears to be acceptable to
    both.


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/svn-auth-x509@1612975 13f79535-47bb-0310-9956-ffa450edef68