Return string by reference instead of value from ASN.1 library.
Improves performance of SNMP queries.


git-svn-id: http://yate.null.ro/svn/yate/trunk@5623 acf43c95-373e-0410-b603-e72c3f656dc1
Fixed SNMP Counter64 implementation.


git-svn-id: http://yate.null.ro/svn/yate/trunk@5624 acf43c95-373e-0410-b603-e72c3f656dc1