Merged from trunk
Added stub for ETag.cc
Set up stub_libauth.cc return values properly
*broken*: stubify CacgeDigest.cc
Stub-ified store_digest.cc, fixed stub_CacheDigest.cc
Improve stub_mem.cc, use it in testSBuf
Completed stubification of cache_manager.cc
Revert stubification of mem.cc in testSBuf
stub-ify whois.cc
More widely use stub_time.cc
Stubify wccp2.cc
stub-ified SwapDir.cc
Stub-ified carp.cc
stub-ified tunnel.cc and StoreMeta.cc
Small fixes to wccp2 and SwapDir stubs as suggested during audit
Defined STOREMETA_SOURCE source files group for StoreMeta-related files
Merge from staging branch: prepare and use more stubs in the unit tests
Bug 3906: Filedescriptor leaks on snmp
author: Alex Rousskov <rousskov@measurement-factory.com>, Christos Tsantilas <chtsanti@users.sourceforge.net>

Coordinator should not send SNMP client FD to strands when broadcasting SNMP
requests. Strands do not need the descriptor and were forgetting to close it,
causing one FD leak on every SNMP query in SMP mode.

Enhance Ipc::TypedMsgHdr to be able to tell whether the message has a FD.

This is a Measurement Factory project
SourceFormat Enforcement
Fix stub_external_acl on icc