2002 04 23 thl
INPUT:  Mon, 5 Jan 2001 12:34:56 +0200 (MET DST)
OUTPUT: Mon, 05 Jan 2001 12:34:56 +0000
Problem#1: 5 Jan 2001 was a Friday. TAI currently parses and keeps the day of week but doesn't check
Problem#2: TAI currently parses but ignores and therefore looses time zone information

- tm_parse(buf,fmt,tm) -> tm_parse(buf,buflen,fmt,tm)
- add exception support