first round of s/sprintf/snprintf/; the rationale is: truncate error messages rather than buffer overflow; otherwise, assert that no buffer overflow occurred.  In some cases, error handling could be added.

(ConfigReply) for the error messages.

_db_destroy functions.

Karsten Kuenne @ rentec.com (ITS#4506)

were modified. Also use tmpmem for the constructed filter.

remove syncrepl stuff from Operation struct