Fix most critical warnings in the core LDAP library code:
AIX has snprintf() so we now #define HAVE_SNPRINTF there.
Use snprintf() instead of sprintf() in ldap_perror().
Use snprintf() instead of sprintf() in ldap_init_getfilter_buf()
and improve error reporting for bad regular expressions.
git-svn-id: svn://10.0.0.236/trunk@140507 18797224-902f-48f8-a5cc-f745e15eee43