don't allow OIDs that are a mix of numeric and non-numeric fields.

  in slap_sasl_getdn, test id, not dn. dn is still NULL
  also, don't check for trailing slash
  in slap_sasl_bind, initialize reslen to 0

Fixes billionth second since epoch bug.

	patch was provided by craig.rawlins@qld.gov.au (ITS#1289)

finish the prefious fixes... it is really hard to commit a truly good patch without even a chance to check if it is compilable ;)

Gohman)

some cosmetics and minor problems fixed, pointed out by Mei-Hui Su (c++-style comments, newlines etc.)