FreeSWITCH-FS-8767

FreeSWITCH: Add WIN32 strerror_s() variant to custom switch_strerror_r() helper function and fix more strerror_r() users.

Convert mod_xml_cdr, mod_json_cdr and mod_conference to the new function.

Signed-off-by: Stefan Knoblich <stkn@openisdn.net>